# Fileset

[d4nh00263f.pdf](https://mdr.nims.go.jp/filesets/ff478766-1278-48da-81a5-2b7f61547607/download)

## Creator

Mindaugas Juodėnas, Nadzeya Khinevich, Gvidas Klyvis, [Joel Henzie](https://orcid.org/0000-0002-9190-2645), Tomas Tamulevičius, Sigitas Tamulevičius

## Rights



## Other metadata

[Lasing in an assembled array of silver nanocubes](https://mdr.nims.go.jp/datasets/a64248b0-6268-44db-ace6-e9a644c66083)

## Fulltext

Lasing in an assembled array of silver nanocubes142 |  Nanoscale Horiz., 2025, 10, 142–149 This journal is © The Royal Society of Chemistry 2025Cite this: Nanoscale Horiz., 2025,10, 142Lasing in an assembled array of silver nanocubes†Mindaugas Juodėnas, *a Nadzeya Khinevich, a Gvidas Klyvis,a Joel Henzie, bTomas Tamulevičius a and Sigitas Tamulevičius aWe demonstrate a surface lattice resonance (SLR)-based plasmonicnanolaser that leverages bulk production of colloidal nanoparticlesand assembly on templates with single particle resolution. SLRsemerge from the hybridization of the plasmonic and photonicmodes when nanoparticles are arranged into periodic arrays andthis can provide feedback for stimulated emission. It has beenshown that perfect arrays are not a strict prerequisite for producinglasing. Here, we propose using high-quality colloids instead. Silvercolloidal nanocubes feature excellent plasmonic properties due totheir single-crystal nature and low facet roughness. We usecapillarity-assisted nanoparticle assembly to produce substratesfeaturing SLR and comprising single nanocubes. Combined withthe laser dye pyrromethene-597, the nanocube array lases at574 nm with o1.2 nm linewidth, o100 lJ cm�2 lasing threshold,and produces a beam with o1 mrad divergence, despite less-than-perfect arrangement. Such plasmonic nanolasers can be producedon a large-scale and integrated in point-of-care diagnostics, photo-nic integrated circuits, and optical communications applications.IntroductionThe demand for miniaturization and improved efficiency ofcoherent light-emitting devices has steadily increased overtime.1 Small lasers operating at the nanoscale can benefitapplications such as optical communications, sensing, bioima-ging, photonic circuits, etc.,2 where a superior size-to-efficiencyratio and decrease in power requirements are particularlyattractive. Making nanolasers requires ultimate control of lightfields at the nanoscale, and metasurfaces, 2D collections ofnanostructures, are excellent at this task. In particular, plas-monic metasurfaces enable precise control over light–matterinteractions leading to enhancements in light emission, con-finement, and manipulation by squeezing electromagneticfields to subwavelength scales in the near field.3Plasmonic metasurfaces can feature surface lattice reso-nances (SLRs) – collective in-phase excitations formed bylocalized surface plasmons (LSP) of nanoparticles and diffrac-tive photonic modes of the lattice. These SLRs have beenextensively studied and reviewed.4 One of the applications ofthese hybrid plasmonic–photonic modes is light amplificationand stimulated emission.1,5,6 When a SLR-supporting plasmo-nic system is in contact with a medium that can provide gain,the lattice resonance acts as a feedback mechanism, amplifiesa Institute of Materials Science, Kaunas University of Technology, K. Baršausko St.59, Kaunas LT-51432, Lithuania. E-mail: mindaugas.juodenas@ktu.ltb Research Center for Materials Nanoarchitectonics (MANA), National Institute forMaterials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan† Electronic supplementary information (ESI) available: More details on methodsand materials and experiments. See DOI: https://doi.org/10.1039/d4nh00263fReceived 6th June 2024,Accepted 21st October 2024DOI: 10.1039/d4nh00263frsc.li/nanoscale-horizonsNew conceptsSmall plasmonic nanolasers based on surface lattice resonance are aunique counterpart to 2D distributed feedback lasers by exclusivelyutilizing localized surface plasmon resonance supporting scatteringunits. Although they have been extensively researched since 2013, thesenanolasers have predominantly been fabricated using bottom-uptechniques like physical vapor deposition, resulting in polycrystallinenanoparticles. This universally leads to diminished scattering propertiescompared to those calculated in numerical models, introducingadditional absorptive losses due to grain boundary scattering ofplasmons. Moreover, a critical question in the field has been: howmuch order is necessary for these plasmonic systems to sustain lasingmodes? Interestingly, it has been found that perfect order is not essential;in fact, a certain degree of disorder can enhance lasing characteristics.Thus, our work demonstrates a conceptually new way of thinking aboutthe fabrication of these systems: employing mass-producedmonocrystalline silver nanocubes as building blocks and assemblingthem on templates for plasmonic nanolasers. Using template-assistedassembly with single-particle resolution on a large scale, our systemsprovide lasing feedback and coherent light emission on-par withpolycrystalline counterparts in the existing research—but on a scalableplatform. This insight challenges the conventional need for highlyordered, cleanroom-produced systems and presents a new method tocreate more cost- and time-efficient, robust plasmonic nanolasers.NanoscaleHorizonsCOMMUNICATIONOpen Access Article. Published on 22 October 2024. Downloaded on 4/16/2025 1:47:35 AM.  This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.View Article OnlineView Journal  | View Issuehttps://orcid.org/0000-0002-0517-8620https://orcid.org/0000-0001-9348-3918https://orcid.org/0000-0002-9190-2645https://orcid.org/0000-0003-3879-2253https://orcid.org/0000-0002-9965-2724http://crossmark.crossref.org/dialog/?doi=10.1039/d4nh00263f&domain=pdf&date_stamp=2024-10-28https://doi.org/10.1039/d4nh00263fhttps://rsc.li/nanoscale-horizonshttp://creativecommons.org/licenses/by/3.0/http://creativecommons.org/licenses/by/3.0/https://doi.org/10.1039/d4nh00263fhttps://pubs.rsc.org/en/journals/journal/NHhttps://pubs.rsc.org/en/journals/journal/NH?issueid=NH010001This journal is © The Royal Society of Chemistry 2025 Nanoscale Horiz., 2025, 10, 142–149 |  143photoluminescence (PL) and can generate light that is bothspatially and temporally coherent.The first SLR-based nanolasers were made using electronbeam deposited gold7 and silver8 nanocylinders and organicdyes. Subsequent research expanded on this foundation toachieve wavelength tunability via the refractive index9 andstretching of elastomer substrates,10 direction of emissioncontrol via multiple lattice modes,11–13 and switching usingmagnetic fields.14 Apart from dyes, quantum dots15–18 and up-converting nanoparticles19 have also been used as gain materi-als. Emission wavelengths from UV using aluminum nano-particles to NIR using gold have been demonstrated, and acombination thereof accomplished white-light lasing.20While most reported SLR-based nanolasers are fabricatedusing either e-beam lithography7,9,12,14,20–22 or the PEELmethod (a combination of phase-shifting photolithography,etching, electron-beam deposition and lift-off of the film),23recent studies have shown that nanolasing can still occur evenwhen a significant fraction of nanoparticles is absent from thearray or the lattice order is decreased.12,24,25 Interestingly,removing some fraction of particles can even help to outcouplelight and increase the slope of the input–output curve whilemaintaining a similar threshold.25 This intriguing findingsuggests that defect-free lattice fabrication through lithographymay not be strictly necessary and opens the door to bottom-upmethods that can offer improved scalability and cost at theexpense of accuracy and precision.An attractive prospect in this regard is the use of colloidalnanoparticles.26 Highly crystalline colloids can be synthesizedon a large scale.27 Crystallinity ensures superior scattering-to-absorbance ratios versus physically deposited polycrystallinematerials with grain boundaries and rough facets that generateabsorptive damping.28,29 Furthermore, these colloids are avail-able in a variety of shapes, which could enable intelligentengineering of hot spots and facilitate anisotropic Purcellenhancement of the gain media for tunable devices.30,31 Thechallenge then lies in arranging these nanoparticles in amanner conducive to providing lasing feedback.Template-assisted nanoparticle assembly is a robust techni-que that can address this task.32–34 A variation of it has beenused to produce a colloid-based nanolaser, where drop castingin combination with stamping of a patterned elastomer moldyielded clusters of nanoparticles.35 Capillarity-assisted particleassembly (CAPA) is another variation that allows a high degreeof control of the number of particles per unit cell, down tosingle particle precision.35,36 In earlier work, we have shownthat this method can produce nanoparticle assemblies on alarge scale (41 cm2) and can feature high-quality SLRs.26,37In this study, we exploit the template-assisted approach tofabricate nanolasers using single, monocrystalline Ag nano-cubes arranged in a subwavelength lattice (Fig. 1). By leveragingCAPA we successfully formed square plasmonic arrays featuringa sharp SLR. We then demonstrate lasing in the presence ofa fluorescent dye with a threshold comparable to that ofsubstrates developed using lithography-based methods. Wecomprehensively characterize the lasing emission, includingparameters such as emission spectra, threshold, beam profile,and polarization.ResultsSLR-based feedback design and nanolaser fabricationNanolaser design. The design of a nanolaser with SLR-basedfeedback, not unlike any other optically pumped laser, requiresa good match between material properties and excitation con-ditions. Achieving population inversion and stimulated emis-sion at the designed wavelength relies on engineering a spectraloverlap of the three major components: the pump needs tocoincide sufficiently with the absorption of the gain medium,and the photoluminescence (PL) of the gain needs to match theresonant frequency of the resonator. We chose the pumpingsource to be our entry point to this problem and opted to usethe second harmonic of the Yb:KGW laser at 515 nm, emitting270 fs pulses. Pyrromethene 59738,39 (P597) was then an excel-lent spectral match for the pump wavelength with a highconversion rate (430%) and a proven track record as a laserdye.40,41 P597 has a strong emission peak centered at B580 nm,which is attainable for silver photonics.The next step is designing the feedback mechanism, whichin this case is the SLR of the plasmonic Ag nanocube array. Theempty lattice band structure (Fig. 2A) of a square array with aperiodicity of 400 nm in the PDMS environment (n = 1.42)features a flat band (zero group velocity) at the G point with awavelength of B562 nm, matching the PL of the dye (Fig. 2B). Ahigh density of optical states is thus expected at this point,which may be sufficient to provide lasing feedback.7 We thenpopulate this lattice using plasmonic nanoparticles to form ahigh-quality SLR.The quality factor of the SLR is highest when the localizedsurface plasmon resonance (LSPR) of individual nanoparticlesis somewhat blue-shifted with respect to the Rayleigh anomaly(RA) of the lattice (marked as solid lines in Fig. 2A and dashedFig. 1 A nanolaser based on assembled colloidal nanoparticles. Sche-matic of an optically pumped nanolaser device comprising a self-assembled array of monocrystalline Ag nanocubes and organic dye. Whenpumped beyond the threshold using 515 nm light, the device lases at574 nm, consistent with the fluorescence of the pyrromethene-597 dyeand surface lattice resonance-based feedback.Communication Nanoscale HorizonsOpen Access Article. Published on 22 October 2024. Downloaded on 4/16/2025 1:47:35 AM.  This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.View Article Onlinehttp://creativecommons.org/licenses/by/3.0/http://creativecommons.org/licenses/by/3.0/https://doi.org/10.1039/d4nh00263f144 |  Nanoscale Horiz., 2025, 10, 142–149 This journal is © The Royal Society of Chemistry 2025lines in Fig. 2C and D). Since we have established the spectrallocation of the flat band in the previous step, the target is tofind nanoparticles with a blue-shifted scattering peak andminimal absorption. We use Ag nanocubes because they canbe synthesized in a monocrystalline form with smooth facetsand we expect them to have an improved scattering-to-absorbance ratio compared to vacuum-deposited material.42We ran electromagnetic calculations using a nanocube geome-try and found that a = 65 nm edge length particles will fit thescattering requirement (blue shift with respect to the RA) verywell (Fig. 2C shows the calculated scattering cross-section). Insubsequent calculations, we set periodic boundary conditionswith a periodicity of 400 nm. Unsurprisingly, the systemfeatures a strong resonance at 581 nm (Fig. 2D), and the electricfield intensity distribution at this wavelength (Fig. 2E) showed astanding wave pattern as well as strong hot spots around thenanoparticles, characteristic of the delocalized photonic-plasmonic SLR mode. The calculated dip in transmittancehas a FWHM of B5.8 nm, resulting in a theoretical Q factorof B100 and overlapping the PL of the gain.Nanolaser fabrication. We used CAPA to position the synthe-sized colloidal nanoparticles with single-particle resolution (seethe ESI† for the synthesis method).43 To use this technology, apatterned template is required, which we produce by molding aPDMS replica from a silicon master prepared by commonnanofabrication routes (Fig. 3A). A distinct advantage is thatthe replication process can be repeated multiple times withoutcompromising the structure, minimizing the need for expen-sive lithography processes associated with nanofabricationwhile ensuring reproducibility (Fig. 3B). A scheme of the CAPAdeposition process is shown in Fig. 3C, where the colloidalsolution is injected between the PDMS template and a station-ary glass slide. The template is then translated relative to thelatter, and its temperature is elevated until nanoparticlesaccumulate at the meniscus. The nanocubes are coated by athin layer of poly-vinyl-pyrrolidone (PVP, B2 nm). This aids thestability of the colloid, especially since dimethylformamide thatwe use is a theta-solvent for PVP. Colloidal stability is of utmostimportance for single particle assembly, as agglomeratingnanoparticles can either get stuck in the colloidal solutionand prevent single particles to access the template, or getdeposited on the template as a large defect, which also distortsthe assembly process around it. Under optimal conditions, thenanoparticles are trapped in the pattern on PDMS with a single-particle resolution as the solution withdraws. An SEM micro-graph of an assembly is shown in Fig. 3D and a full samplecamera photograph, optical dark-field micrograph, and a largearea SEM micrograph are displayed in the ESI,† Fig. S1.There is some unintended disorder within these arrays,similar to the purposely introduced disorder reported in pre-vious work.25 The measured extinction of the assembly(Fig. 3E, red curve) still showed a high-quality SLR resonance(l = 572 nm, Q = 66), which matches the calculation in Fig. 2Dand overlaps the gain PL (Fig. 3E, pink curve).After assembly, the substrates are preemptively soaked in a5 mM P597 solution in DMSO : EtOH (2 : 1) overnight, improvingstability and preventing dye diffusion into PDMS during experi-ments (Fig. 3C). Finally, a drop of dye solution is placed on thesubstrate and covered with a cover slip. We found that thenanoparticles stay in place because the trap size is very close tothe dimensions of the particles, leaving no room for movementand even requiring substantial persuasion to remove them.Fig. 2 Nanolaser design. (A) Empty square lattice band structure (L = 400 nm, n = 1.42) with an indicated SLR location (dashed red line) forming a flatband at the G point. Nanolaser pumping wavelength is indicated by a dashed green line, overlapping the absorbance of the dye. (B) Thephotoluminescence and absorbance of the gain (P597 laser dye). (C) Calculated scattering cross-section spectrum of a = 65 nm edge length Agnanocubes. The vertical dashed line indicates the location of the RA at the G point. (D) Calculated transmittance spectrum of Ag nanocubes in the array(shaded curve is a Lorentzian fit and the location of the Rayleigh anomaly is indicated by a vertical dashed line). (E) Calculated electric field intensitydistribution of Ag nanocubes in the array at the SLR wavelength (l = 581 nm) when illuminated by a normally incident, x-polarized plane wave.Nanoscale Horizons CommunicationOpen Access Article. Published on 22 October 2024. Downloaded on 4/16/2025 1:47:35 AM.  This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.View Article Onlinehttp://creativecommons.org/licenses/by/3.0/http://creativecommons.org/licenses/by/3.0/https://doi.org/10.1039/d4nh00263fThis journal is © The Royal Society of Chemistry 2025 Nanoscale Horiz., 2025, 10, 142–149 |  145Fig. 3F shows the experimental setup to evaluate nanolasingcharacteristics. We pump our devices with a collimated,Yb:KGW second harmonic 515 nm wavelength, 2.4 mm (1/e2)size beam spot with a controlled linear polarization state. Weused 50 Hz frequency to avoid excessive dye bleaching andcollect normal emission from the sample in free space using afiber-coupled spectrograph and a CMOS camera.Nanolaser characterizationClaims of lasing typically require three key features indicatingthe required level of spectral and temporal coherence of theemitted light: (i) a clear threshold of pumping power beyondwhich the slope of the input–output curve changes; (ii) asignificant narrowing of the PL peak as the system crossesthe lasing threshold, indicating the transition from sponta-neous to stimulated emission; (iii) the emitted light must forma beam typical of the resonator.44 Fig. 4 summarizes our resultsregarding each of these points.Threshold and linewidth. We ran all characterization experi-ments using two pump polarizations: TM and TE, schematicallyshown in Fig. 4A and E, respectively. The characterization oflasing threshold is shown in Fig. 4B and F. As the pump fluenceincreased above the threshold value, the intensity of theemission increased faster than that of the PL emission back-ground, which is attributed to the nonlinearity associated withstimulated emission. The PL intensity before the threshold isvery small in our data because of how the experiment is set up –the spectrograph is coupled with a low-NA fiber coupler andlocated far from the sample, effectively eliminating all highlydivergent PL signals. We recorded a threshold of 80 mJ cm�2using both polarizations by repeatedly scanning the fluenceclose to the threshold to acquire more data points. Theseresults could be further improved by precision engineeringthe overlap between the SLR and the gain emission, as wellas experimenting with pumping strategies.We believe we achieve this competitive, and in many casessuperior, threshold compared to reports of similarsystems11,21,29,35,45,46 (see the ESI,† Table S1, where we sum-marize the characteristics of similar systems in the literature),despite the unideal nanoparticle lattice because of enhancedplasmonic nanoparticle qualities enabled by monocrystallinityand low facet roughness, which decrease if not eliminateelectron scattering at crystal boundaries and associated absorp-tive damping.28 This experimental observation positions ourwork as a significant step forward towards scalable alternativeto standard lithography based solutions, connecting the dotsFig. 3 Nanolaser fabrication based on nanoparticle self-assembly. (A) A master stamp is designed for a lattice resonance at a target wavelength andfabricated following standard lithography patterning and etching routines. (B) The pattern is transferred to a PDMS film via soft-lithography and thisprocess can be repeated many times, providing templates for numerous devices. (C) Ag nanocubes featuring a LSPR close to the target wavelength areassembled into the template using CAPA. The devices are then soaked in a dye solution before being interfaced with an additional drop on top, confinedby a glass cover slip. (D) An SEM micrograph of assembled nanocubes in a PDMS template. Inset shows a TEM micrograph of the nanocubes.(E) Experimental spectra of nanocubes in solution vs. in array, and the PL spectrum of the dye. The vertical dashed line indicates the location of the RA atthe G point in PDMS. (F) The nanolasers are characterized after pumping with a 270 fs 515 nm laser using a spectrograph and a CMOS camera (L – beamreducer; l/2 – half-waveplate, M – mirrors, NF – neutral density and notch filters).Communication Nanoscale HorizonsOpen Access Article. Published on 22 October 2024. Downloaded on 4/16/2025 1:47:35 AM.  This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.View Article Onlinehttp://creativecommons.org/licenses/by/3.0/http://creativecommons.org/licenses/by/3.0/https://doi.org/10.1039/d4nh00263f146 |  Nanoscale Horiz., 2025, 10, 142–149 This journal is © The Royal Society of Chemistry 2025between SLR-based light-emitting nanophotonics, nanoparticlestatistics, and colloid based template-assisted nanoparticleassembly.The rapid increase in intensity beyond the threshold isaccompanied by the emergence of a narrow peak around theSLR wavelength, suggesting the onset of lasing (Fig. 4C and G).Lasing occurred close to the flat band edge (B574 nm) of thelattice as intended (Fig. 2A). We observed slight wavelengthvariations because of the open cavity system, leading toinstability of the refractive index environment during theexperiment, i.e., evaporation and diffusion of the dye solvent.The PL linewidth starts at B45 nm FWHM (Fig. 2B) and rapidlydecreases above the threshold to o1.2 nm, limited by ourspectrograph resolution. In some cases, we observe a slightincrease in linewidth with pumping power, but this is notuncommon for similar nanolasers.45 Spectral narrowing is atelltale sign of temporal coherence, although a better evalua-tion is using the second-order correlation function g(2). Unfor-tunately, this measurement was not available at this time, andeven if it was, it is challenging to acquire accurate results for aplasmonic nanolaser with gain materials composed of organicdye.7Beam profile and polarization. The images of the laser beamwere taken above the threshold by placing a CMOS camera atvarying distances. Fig. 4D and H show these images taken at22.5 cm for the two orthogonal polarizations, converted toangular coordinates (images at different distances are shownin Fig. S2, ESI†). In both cases, the beam consists of a multitudeof horizontal or vertical lines, indicating that the device oper-ates similarly to 1D distributed feedback (DFB) lasers.30,47 Webelieve that the number and density of lines are associated withthe quality of the nanoparticle lattice. We measured 1/e2 of thenarrow dimension of one of the lines (which remains almostconstant at varying distances) profile in angular coordinatesand estimated the divergence of individual lines to o1 mrad.The output beam of the nanolaser above the threshold wasstrongly linearly polarized and followed one of the squarelattice directions. If the polarization of the exciting beam didnot match the lattice orientation, the emission still did,with variations in intensity corresponding to the projection ofthe electric field vector of the pump onto the lattice direction.A characterization of the polarization state is displayed inFig. S3 (ESI†).DiscussionApart from the characteristics discussed above, other phenom-ena similar to lasing must be ruled out.44,48,49 Specifically,amplified spontaneous emission (ASE) can appear similar tolasing. It involves the stimulated amplification of PL by a singlepass through the gain volume, irrespective of the feedbackmechanism.50 This effect can especially be difficult to discri-minate against lasing if the designed wavelength is very close tothe PL peak of the emission, such as in our case (Fig. 2B). Likelasing, ASE can show a threshold behavior (albeit weaker andless consistent), linewidth narrowing, and produce somewhatdirectional emission. But the FWHM is usually in the range of acouple of tens of nm, the emitted wavelength does not dependon resonator configuration and the emission is unpolarized,contrary to the data presented here.In our results, the FWHM is consistently o1.2 nm, which isthe resolution limit of our spectrograph. We also tested oursetup using a slightly different resonator (420 nm lattice, samenanocubes). The lasing peak followed this change (Fig. S4,ESI†), indicating that emission strongly depends on theFig. 4 Nanolaser characteristics. (A) and (E) The nanolaser emits a beam that follows the polarization of the pump and is extended in the same direction.(B) and (F) The dependence of emission intensity and the FWHM of the lasing peak on the pumping fluence, exhibiting a clear threshold behavior. (C) and(G) Emission spectra collected normal to the nanolaser plane above the lasing threshold. (D) and (H) The beam profile of the nanolaser in angularcoordinates captured by a CMOS camera 22.5 cm away from the device with no collection optics.Nanoscale Horizons CommunicationOpen Access Article. Published on 22 October 2024. Downloaded on 4/16/2025 1:47:35 AM.  This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.View Article Onlinehttp://creativecommons.org/licenses/by/3.0/http://creativecommons.org/licenses/by/3.0/https://doi.org/10.1039/d4nh00263fThis journal is © The Royal Society of Chemistry 2025 Nanoscale Horiz., 2025, 10, 142–149 |  147resonator. Moreover, the beam our devices emit is clearlylinearly polarized and follows the resonator geometry. Finally,in some cases we could observe the emergence of ASE at higherpumping powers, when it starts to outcompete lasing (Fig. S5,ESI†). This observation allows us to unambiguously distinguishbetween these emission modes.Another process that may be mistaken for lasing is the edge-emission of waveguided modes. In this case, the thresholdbehavior is unexpected, which we consistently observe in oursystem. Moreover, we collect our data at the normal to thedevice surface. 1D distributed feedback (DFB) lasers emitelongated beams with low divergence along the feedback axisand high divergence perpendicular to it, which emerges as afan-like beam.44,51 We observe similar fan-like emission withorientation aligned to one of the lattice directions. This obser-vation strongly suggests that the 2D array of nanoparticlesessentially behaves as a collection of 1D arrays and emits aset of these fan-like beams. Plasmonic nanoparticles predomi-nantly support electric modes, and dipolar electric modesmainly radiate, couple, and provide feedback in directionsorthogonal to the axis of the induced dipole. 2D feedbackand annular beams can be achieved by simultaneously provid-ing TM and TE excitation by switching to waveguide-hybridizedSLR modes (nanoparticles on a thin film)16 or high-NAobjective-based excitation.52Finally, we left our devices operating and measured theexpected lifetime (Fig. S6, ESI†). Although we were using anopen system and a liquid dye solution, these nanolasers stillmaintained narrow linewidth emission for 15–30 minutes,depending on polarization. TE configuration extended the life-time approx. 2-fold, but at a lower overall intensity. Replace-ment of the dye solution allows the used devices to regenerateand they can be operated again, indicating that the resonator isnot damaged and the nanoparticles stay in place. Nanoparticleassemblies themselves and the resulting SLR stay stable for along time.26 Unless the nanoparticles are locally affected bypumping radiation—either changing shape and consequentlylosing the SLR, or getting dislodged from the template, thedevice can be operated indefinitely, as long as the dye solutionis stable as indicated above.The performance of our devices could be further improved:the threshold could be lowered by fine-tuning the interplaybetween the dye emission and the SLR, by setting up moreefficient pumping schemes and conditions, as well as enhan-cing the experimental methods to more accurately estimate theonset of lasing; the efficiency could be further improved byselecting more efficient fluorescent materials, such as quantumdots as well as envisioning more efficient pumping and deviceschemes to suppress the loss channels such as amplifiedspontaneous emission, edge emission, waveguided in-planeemission, etc.Overall, the demonstrated results clearly show that theemission from our devices strongly corresponds to the resona-tor used with a clearly defined threshold and polarization state.Therefore, our experimental observations strongly favor theclaim of nanolasing from these assembled colloidal nanocubearrays. We believe our results tie together the three importantfacets of light-emitting nanophotonics devices: SLR-basedcoherent light emission, large scale colloid-based template-assisted nanoparticle assembly, and nanoparticle statisticsindicating the small relevance of disorder in these systems.We showed experimentally, that such devices can be producedon a cm2 scale, maintaining good light emission characteristicsthat are comparable or in some cases superior to lithography-based polycrystalline counterparts. We expect important appli-cations using such platforms to follow in areas like sensing, on-chip communications, integration with flexible substrates, andstructured light,53,54 especially where our technology can beleveraged for large scale production.ConclusionsWe presented a novel approach to develop a surface latticeresonance-based plasmonic nanolaser with competitive char-acteristics. We used a template-assisted technique to assemblehighly crystalline silver colloidal nanocubes into periodicarrays. These plasmonic substrates featured a high-qualitySLR, which served as a feedback mechanism for stimulatedemission. We demonstrated a nanolaser with a narrow line-width of o1.2 nm, a lasing threshold of o100 mJ cm�2, and abeam characteristic of the resonator with minimal divergenceand a clear polarization state. We claim that our devices arecomparable to lithography-made counterparts by exploiting theenhanced emission by defects in the lattice while maintaining alow threshold and scalability. These attributes, coupled withthe potential for large-scale production leveraging colloidalmethods and template-assisted assembly techniques, positionour devices as promising candidates for applications. Suchplasmonic arrays can be inexpensively transferred onto almostany substrate, allowing easy integration in applications rangingfrom point-of-care diagnostics to photonic integrated circuitsand optical communications systems.Author contributionsConceptualization: MJ, JH, TT; data curation: MJ, NK; formalanalysis: MJ, NK; funding acquisition: ST; investigation: MJ,NK, GK; methodology: MJ, TT; project administration: MJ, TT,ST; resources: JH, TT, ST; software: MJ; supervision: MJ, TT, ST;validation: MJ, NK, GK; visualization: MJ; writing – originaldraft: MJ, NK, GK; writing – review & editing: MJ, NK, GK, JH,TT, ST.Data availabilityData supporting the findings of this study are available athttps://doi.org/10.5281/zenodo.13890740 and from the corres-ponding author upon reasonable request.Communication Nanoscale HorizonsOpen Access Article. Published on 22 October 2024. Downloaded on 4/16/2025 1:47:35 AM.  This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.View Article Onlinehttps://doi.org/10.5281/zenodo.13890740http://creativecommons.org/licenses/by/3.0/http://creativecommons.org/licenses/by/3.0/https://doi.org/10.1039/d4nh00263f148 |  Nanoscale Horiz., 2025, 10, 142–149 This journal is © The Royal Society of Chemistry 2025Conflicts of interestThere are no conflicts to declare.AcknowledgementsThis research was performed within project ‘‘LaSensA’’ underthe M-ERA.NET scheme and was funded by the ResearchCouncil of Lithuania (LMTLT), agreement No. S-M-ERA.NET-21-2, National Science Centre (Poland), agreement No. UMO-2020/02/Y/ST5/00086, Saxon State Ministry for Science, Cultureand Tourism (Germany) and co-financed with tax funds on thebasis of the budget passed by the Saxon state parliament.JH thanks the Japan Society for the Promotion of Science(JSPS) Grants-in-Aid for Scientific Research Kakenhi Program(20K05453).References1 Y. Liang, C. Li, Y.-Z. Huang and Q. Zhang, PlasmonicNanolasers in On-Chip Light Sources: Prospects and Chal-lenges, ACS Nano, 2020, 14, 14375–14390.2 R.-M. Ma and R. F. Oulton, Applications of nanolasers, Nat.Nanotechnol., 2019, 14, 12–22.3 N. Meinzer, W. L. Barnes and I. R. Hooper, Plasmonic meta-atoms and metasurfaces, Nat. Photonics, 2014, 8, 889–898.4 A. D. Utyushev, V. I. Zakomirnyi and I. L. Rasskazov, Col-lective lattice resonances: Plasmonics and beyond, Rev.Phys., 2021, 6, 100051.5 J. Guan, et al., Light–Matter Interactions in Hybrid MaterialMetasurfaces, Chem. Rev., 2022, 122, 15177–15203.6 A. Vaskin, R. Kolkowski, A. F. Koenderink and I. Staude,Light-emitting metasurfaces, Nanophotonics, 2019, 8,1151–1198.7 W. Zhou, et al., Lasing action in strongly coupled plasmonicnanocavity arrays, Nat. Nanotechnol., 2013, 8, 506–511.8 A. H. Schokker and A. F. Koenderink, Lasing at the bandedges of plasmonic lattices, Phys. Rev. B: Condens. MatterMater. Phys., 2014, 90, 155452.9 A. Yang, et al., Real-time tunable lasing from plasmonicnanocavity arrays, Nat. Commun., 2015, 6, 6939.10 D. Wang, et al., Stretchable Nanolasing from Hybrid Quad-rupole Plasmons, Nano Lett., 2018, 18, 4549–4555.11 R. Heilmann, K. Arjas and T. K. Hakala, & Päivi Törmä.Multimode Lasing in Supercell Plasmonic NanoparticleArrays, ACS Photonics, 2023, 10, 3955–3962.12 F. Freire-Fernández, et al., Quasi-Random MultimetallicNanoparticle Arrays, ACS Nano, 2023, 17, 21905–21911.13 T. K. Hakala, et al., Lasing in dark and bright modes of afinite-sized plasmonic lattice, Nat. Commun., 2017, 8, 13687.14 F. Freire-Fernández, et al., Magnetic on–off switching of aplasmonic laser, Nat. Photonics, 2022, 16, 27–32.15 J. Guan, et al., Engineering Directionality in Quantum DotShell Lasing Using Plasmonic Lattices, Nano Lett., 2020, 20,1468–1474.16 J. Guan, et al., Quantum Dot-Plasmon Lasing with Con-trolled Polarization Patterns, ACS Nano, 2020, 14,3426–3433.17 R. K. Yadav, et al., Room Temperature Weak-to-StrongCoupling and the Emergence of Collective Emission fromQuantum Dots Coupled to Plasmonic Arrays, ACS Nano,2020, 14, 7347–7357.18 D. Xing, et al., Ligand Engineering and Recrystallization ofPerovskite Quantum-Dot Thin Film for Low-Threshold Plas-monic Lattice Laser, Small, 2022, 18, 2204070.19 A. Fernandez-Bravo, et al., Ultralow-threshold, continuous-wave upconverting lasing from subwavelength plasmons,Nat. Mater., 2019, 18, 1172–1176.20 J. Guan, et al., Plasmonic Nanoparticle Lattice Devices forWhite-Light Lasing, Adv. Mater., 2023, 35, 2103262.21 J. Guan, et al., Far-field coupling between moiré photoniclattices, Nat. Nanotechnol., 2023, 1–7.22 W. Wang, et al., Ultrafast Dynamics of Lattice PlasmonLasers, J. Phys. Chem. Lett., 2019, 10, 3301–3306.23 J. Henzie, M. H. Lee and T. W. Odom, Multiscale patterningof plasmonic metamaterials, Nat. Nanotechnol., 2007, 2,549–554.24 A. H. Schokker and A. F. Koenderink, Lasing in quasi-periodic and aperiodic plasmon lattices, Optica, 2016, 3,686–693.25 A. H. Schokker and A. F. Koenderink, Statistics of Rando-mized Plasmonic Lattice Lasers, ACS Photonics, 2015, 2,1289–1297.26 M. Juodėnas, T. Tamulevičius, J. Henzie, D. Erts andS. Tamulevičius, Surface Lattice Resonances in Self-Assembled Arrays of Monodisperse Ag Cuboctahedra, ACSNano, 2019, 13, 9038–9047.27 A. R. Tao, S. Habas and P. Yang, Shape Control of ColloidalMetal Nanocrystals, Small, 2008, 4, 310–325.28 N. Khinevich, et al., Size and crystallinity effect on theultrafast optical response of chemically synthesized silvernanoparticles, J. Materiomics, 2024, 10, 594–600.29 S. Deng, et al., Ultranarrow plasmon resonances fromannealed nanoparticle lattices, Proc. Natl. Acad. Sci., 2020,117, 23380–23384.30 M. P. Knudson, et al., Polarization-Dependent Lasing Beha-vior from Low-Symmetry Nanocavity Arrays, ACS Nano, 2019,13, 7435–7441.31 V. Karanikolas, et al., Plasmon-Triggered Ultrafast Opera-tion of Color Centers in Hexagonal Boron Nitride Layers,ACS Omega, 2023, 8, 14641–14647.32 Y. Yin, Y. Lu, B. Gates and Y. Xia, Template-Assisted Self-Assembly: A Practical Route to Complex Aggregates ofMonodispersed Colloids with Well-Defined Sizes, Shapes,and Structures, J. Am. Chem. Soc., 2001, 123, 8718–8729.33 Y. Cui, et al., Integration of Colloidal Nanocrystals intoLithographically Patterned Devices, Nano Lett., 2004, 4,1093–1098.34 L. Malaquin, T. Kraus, H. Schmid, E. Delamarche andH. Wolf, Controlled Particle Placement through Convectiveand Capillary Assembly, Langmuir, 2007, 23, 11513–11521.Nanoscale Horizons CommunicationOpen Access Article. Published on 22 October 2024. Downloaded on 4/16/2025 1:47:35 AM.  This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.View Article Onlinehttp://creativecommons.org/licenses/by/3.0/http://creativecommons.org/licenses/by/3.0/https://doi.org/10.1039/d4nh00263fThis journal is © The Royal Society of Chemistry 2025 Nanoscale Horiz., 2025, 10, 142–149 |  14935 Y. Conti, N. Passarelli, J. Mendoza-Carreño, L. Scarabelliand A. Mihi, Colloidal Silver Nanoparticle Plasmonic Arraysfor Versatile Lasing Architectures via Template-AssistedSelf-Assembly, Adv. Opt. Mater., 2023, 11, 2300983.36 J. Henzie, S. C. Andrews, X. Y. Ling, Z. Li and P. Yang,Oriented assembly of polyhedral plasmonic nanoparticleclusters, Proc. Natl. Acad. Sci., 2013, 110, 6640–6645.37 M. Juodėnas, et al., Effect of Ag Nanocube OptomechanicalModes on Plasmonic Surface Lattice Resonances, ACSPhotonics, 2020, 7, 3130–3140.38 D. M. AL-Aqmar, H. I. Abdelkader and M. T. H. Abou Kana,Optical, photo-physical properties and photostability ofpyrromethene (PM-597) in ionic liquids as benign green-solvents, J. Lumin., 2015, 161, 221–228.39 W. P. Partridge, N. M. Laurendeau, C. C. Johnson andR. N. Steppel, Performance of Pyrromethene 580 and 597in a commercial Nd:YAG-pumped dye-laser system, Opt.Lett., 1994, 19, 1630–1632.40 Z. Hu, et al., Coherent Random Fiber Laser Based onNanoparticles Scattering in the Extremely Weakly ScatteringRegime, Phys. Rev. Lett., 2012, 109, 253901.41 E. Yariv, S. Schultheiss, T. Saraidarov and R. Reisfeld,Efficiency and photostability of dye-doped solid-state lasersin different hosts, Opt. Mater., 2001, 16, 29–38.42 D. Peckus, et al., Hot Electron Emission Can Lead to Dampingof Optomechanical Modes in Core–Shell Ag@TiO2 Nano-cubes, J. Phys. Chem. C, 2017, 121, 24159–24167.43 T. Kraus, et al., Nanoparticle printing with single-particleresolution, Nat. Nanotechnol., 2007, 2, 570–576.44 I. D. W. Samuel, E. B. Namdas and G. A. Turnbull, How torecognize lasing, Nat. Photonics, 2009, 3, 546–549.45 H. T. Rekola, T. K. Hakala and P. Törmä, One-DimensionalPlasmonic Nanoparticle Chain Lasers, ACS Photonics, 2018,5, 1822–1826.46 T. B. Hoang, G. M. Akselrod, A. Yang, T. W. Odom andM. H. Mikkelsen, Millimeter-Scale Spatial Coherence from aPlasmon Laser, Nano Lett., 2017, 17, 6690–6695.47 K. Yoshida, et al., Electrically driven organic laserusing integrated OLED pumping, Nature, 2023, 621,746–752.48 Scrutinizing lasers, Nat. Photonics, 2017, 11, 139.49 R. Sato, et al., Random Lasing via Plasmon-Induced Cavita-tion of Microbubbles, Nano Lett., 2021, 21, 6064–6070.50 A. J. C. Kuehne and M. C. Gather, Organic Lasers: RecentDevelopments on Materials, Device Geometries, and Fabri-cation Techniques, Chem. Rev., 2016, 116, 12823–12864.51 I. D. W. Samuel and G. A. Turnbull, Organic SemiconductorLasers, Chem. Rev., 2007, 107, 1272–1295.52 G. Heliotis, et al., Emission Characteristics and Perfor-mance Comparison of Polyfluorene Lasers with One- andTwo-Dimensional Distributed Feedback, Adv. Funct. Mater.,2004, 14, 91–97.53 M. L. Fajri, et al., Designer Metasurfaces via NanocubeAssembly at the Air–Water Interface, ACS Nano, 2024, 18,26088–26102.54 J. Mendoza-Carreño, et al., Nanoimprinted 2D-Chiral Per-ovskite Nanocrystal Metasurfaces for Circularly PolarizedPhotoluminescence, Adv. Mater., 2023, 35, 2210477.Communication Nanoscale HorizonsOpen Access Article. Published on 22 October 2024. Downloaded on 4/16/2025 1:47:35 AM.  This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.View Article Onlinehttp://creativecommons.org/licenses/by/3.0/http://creativecommons.org/licenses/by/3.0/https://doi.org/10.1039/d4nh00263f