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Aoi Morimoto, [Yu Yamashita](https://orcid.org/0000-0001-7966-3197), Taiki Sawada, Masaki Ishii, Shun Watanabe, [Jun Takeya](https://orcid.org/0000-0002-7003-1350)

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[Doped interlayers enabling high-mobility p-type organic transistors with copper contact electrodes](https://mdr.nims.go.jp/datasets/a3f5f995-343e-49af-bc07-342e94f96a6a)

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Journal NameDoped interlayers enabling high-mobility p-type organictransistors with copper contact electrodes†Aoi Morimoto,a,b Yu Yamashita,∗a,b, Taiki Sawada,a Masaki Ishiib,c, Shun Watanabe,a, andJun Takeya∗a,babstractThin-film single crystals of organic semiconductors (OSCs) enablesimple and low-cost fabrication of high-mobility organic field-effecttransistors (OFETs) via solution processing. However, injectionbarriers in OFETs limit material selection and device performance.Researchers typically use high-work-function noble metals as con-tact electrodes for p-type OFETs owing to transport levels wellbelow −5.0 eV for ambient stable OSCs. This raises questionsregarding the economic and environmental advantages of OSC-based printed electronics. This study demonstrates high-mobilityOFETs with copper contact electrodes using doped interlayers. Apoly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) interlayerwas laminated on the OSC single crystals. The PTAA interlayerwas chemically doped using aqueous doping solutions, followed byevaporation of copper contact electrodes. Our OFET showed aproper p-type operation with a mobility of 5.0 cm2 V−1 s−1 and on-off ratio of approximately 104. This is in contrast to the casewithout the doped interlayer showing poor performance and a lowmobility of 0.2 cm2 V−1 s−1. This study provides new opportuni-ties for designing devices with a high performance, low cost, andmaterial sustainability.IntroductionAdvancements in organic field-effect transistors (OFETs)1 haveopened avenues for various electronic applications, includinghigh-speed integrated circuits2–4, memory devices5–7, and sen-sors8,9. The use of thin-film single crystals of organic semicon-ductors (OSCs) enhances the mobility and reliability of OFETs,a Department of Advanced Materials Science, Graduate School of Frontier Sciences,University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan. E-mail:takeya@k.u-tokyo.ac.jp.b Research Center for Materials Nanoarchitectonics (MANA), National Institute forMaterials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan. E-mail:YAMASHITA.Yu@nims.go.jp.c Graduate School of Science and Technology, Tokyo University of Science, 2641 Ya-mazaki, Noda, Chiba 278-8510, Japan† Supplementary Information available: See DOI: 00.0000/00000000.thereby providing a way to fabricate integrated devices3,10. Highmobilities exceeding 10 cm2 V−1 s−1 result from innovations inmaterials11–14 and thin-film fabrication techniques10,15–19 forOSCs. These single crystals are formed through a one-shot so-lution process under ambient conditions, underscoring the envi-ronmental and economic sustainability of OSCs.However, carrier injection into OSCs limits device performanceand influences material selection20, which needs to be addressedto expand application areas. OSCs for p-type channels must havethe highest occupied molecular orbital (HOMO) energy levelswell below −5.0 eV vs. vacuum to ensure ambient stability21.This requirement explains the reliance on high-work-function no-ble metals such as platinum and gold as electrodes for propertransistor operation, especially in high-mobility OFETs, whichposes challenges for economic and material sustainability22. Touse an abundant metal, such as copper, with a work function(WF) of 4.6 eV, careful alignment of energy levels at the contactsmust be addressed23,24.Engineering at the electrode-semiconductor interface is crucialfor improving carrier injection into OSCs. Self-assembled mono-layers modify the electrode WF, reducing contact resistance inbottom-contact geometries2. Although this method was effectivefor copper electrodes24,25, the reported contact resistance wasapproximately 1 MΩcm, far exceeding the optimal range neces-sary for high-mobility OFETs. An alternative approach involvesthe use of multiple layers of OSCs with varying energy levelsto reduce injection barriers26. This strategy of employing inter-layers to facilitate charge carrier injection and extraction is, infact, a well-established and highly effective technique in the fieldof photovoltaics, particularly for high-performance organic solarcells27–30. In p-type transistors, molecules with large electronaffinities have been introduced between the electrodes and activelayers to create contact-doping effects31. However, the applicabil-ity of this strategy to copper electrodes with p-type OSCs remainsuncertain owing to the large difference in energy levels. Previ-ous reports were mostly limited to OSCs with a shallow HOMOJournal Name, [year], [vol.],1–7 | 1aHydrophilic glassPTAA layering P-type chemical doping of PTAAPTAAHoleTFPB−BQ TFPB−HQ2H+ + 2e−Electrode evaporation and final device stateTransferringby supplying water300 µmcbAqueous dopant solutionβ-PTSC9-DNBDT-NWdopedPTAAAuSiO2 (100 nm)n-doped SiC9-DNBDT-NW(−5.24 eV)PTAAEnergy (eV)−5.3−5.2−5.1−5.0−4.9Cu−4.8−4.7−4.6Fig. 1 (a) Schematics of the device fabrication, illustrating the process of transfer of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) layeron C9–DNBDT–NW single crystals, chemical doping, and electrode deposition. (b) Chemical structures of PTAA and C9–DNBDT–NW together withthe transport energy levels of employed materials. (c) A polarized microscopy image of the fabricated single-crystal organic field-effect transistors.and instability in air32,33. For bottom-contact geometries, treat-ment of copper electrodes with molecular acceptors increases thework function of the electrodes and the mobility of OFETs operat-ing under ambient conditions34. However, it is unclear whetherthe contact resistance can go below 1 MΩcm with this method.Recent advances in efficient chemical doping and highly dopedmaterials35–39 may provide a way to dope semiconductor activelayers and thus decrease the injection barriers. However, this ap-proach can cause undesirable doping of channels and a decreasein the on-off ratio. Thus, the use of copper or low-work-functionmetals as contact electrodes in high-performance p-type OFETsremains challenging.Here, we propose a new contact structure for OFETsthat enables high-mobility operation using copper elec-trodes by introducing a doped polymer interlayer. Forthe 3,11-dinonyldinaphtho[2,3-d:2’,3’-d’]benzo[1,2-b:4,5-b’]dithiophene(C9–DNBDT–NW)10 single-crystal active layer, weselected the polymeric semiconductor poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (poly(triarylamine) (PTAA)) as theinterlayer material. This choice was motivated by two keyfactors. First, PTAA’s deep HOMO level of approximately−5 eV is well-aligned with that of C9–DNBDT–NW, which isexpected to reduce the hole injection barrier from the elec-trode. Second, PTAA itself possesses a field-effect mobility of0.003 cm2 V−1 s−1 40, which is low relative to C9–DNBDT–NW,ensuring that its insertion does not interfere with FET on/offoperation. In our structure, a thin PTAA interlayer was stackedon the C9–DNBDT–NW single crystal. After the chemical dopingof the PTAA interlayer using an aqueous solution39, coppercontact electrodes were thermally deposited. Our OFET showedproper p-type operation with a mobility of 5.0 cm2 V−1 s−1 andan on-off ratio of approximately 104, which is dramaticallyimproved compared to the case without the doped interlayer.Here, the moderately shallow doping level of the PTAA interlayer,as revealed by X-ray photoelectron spectroscopy (XPS) andultraviolet photoelectron spectroscopy (UPS), enabled the propernormally-off operation. The balanced on-off ratios and mobilitysuggest that the rational use of doped polymer interlayersenables the employment of abundant metals, such as copper, inOFET contact electrodes.Results and DiscussionsOFET Fabrication and CharacterizationTo investigate the effect of the PTAA interlayer between thesource/drain electrodes and C9–DNBDT–NW active layer, wefabricated single-crystal OFETs, as illustrated in Fig. 1. Athin-film single crystal of C9–DNBDT–NW was deposited via thecontinuous edge-casting method10,15 (see Methods section fordetails). The schematic of the fabrication process is presented inFig. 1a. The PTAA interlayer was spin-coated onto a hydrophilicglass substrate with a thickness of less than 10 nm (Fig. S1)and subsequently transferred onto the C9–DNBDT–NW layer. Inthis process, the PTAA interlayer was peeled off the hydrophilicglass substrate by supplying water41. The PTAA interlayer wasthen chemically doped by treatment with an aqueous solutionof benzoquinone (BQ) and tetrakis(pentafluorophenyl)borateanion (TFPB– ). The doping process involves redox reactionsbetween BQ and the organic semiconductor, introducing holesinto the material. This is accompanied by the incorporation of2 | 1–7Journal Name, [year], [vol.],3500300025002000150010005000RCW (Ω cm)-20 -16 -12 -8VG − Vth (V)121086420µint  (cm2 V−1 s−1)8000600040002000RtotalW (Ω cm)200150100500L (μm)VG − Vth (V)−12−16−21-80-60-40-200I D (x10-6 A)-30-20-100VG (V)VD = −1 VL (µm)8247090110150175195-800-600-400-2000200I D (x10-6 A)-30-20-100VD (V)10-810-710-610-510-410-3|I D| (A)-30-20-100VG (V)302520151050|ID | 1/2 (x10-3 A1/2)10-910-810-710-610-510-4|I D| (A)-30-20-100VG (V)-40-30-20-100ID  (x10-6 A)-150-100-50050I D (x10-6 A)-30-20-100VD (V)10-13 10-11 10-9 10-7 10-5 10-3|I D| (A)-30-20-100VG (V)121086420|ID | 1/2 (x10-3 A1/2)10-1010-910-810-710-610-5|I D| (A)-30-20-100VG (V)-2.0-1.5-1.0-0.50.0ID  (x10-6 A)a b cAu /PTAAAu /PTAA dopedVD = −1 V VD = −30 VVD = −1 V VD = −30 VΔVG = −5 Vd e fAu /PTAA dopedAu /PTAAAu /PTAA dopedAu /PTAAΔVG = −5 Vg h iAu /PTAA dopedAu /PTAA dopedAu /PTAA dopedFig. 2 Comparison of OFET characteristics using Au electrodes and PTAA interlayers with and without chemical doping. Transfer curves in the(a) linear regime (VD at −1 V) and (b) saturation regime (VD at −30 V) and (c) the output characteristics of the OFET fabricated without chemicaldoping. The channel length (L) is 65 µm. Transfer curves in the (d) linear regime (VD at −1 V) and (e) saturation regime (VD at −30 V) and (f) theoutput characteristics of the OFET fabricated using the chemical doping process. L is 70 µm. In (c) and (f), employed VG values are −30 V, −25 V,−20 V, −15 V, −10 V, −5 V, 0 V, and 5 V. (g) Transfer curves in the linear regime with different L for OFET with doped PTAA and (h) correspondingtransfer length method (TLM) plots at various VG −Vth. (i) Dependence of RCW and µint on VG −Vth.TFPB– anions for charge compensation. Finally, the source/drainelectrodes were fabricated via thermal deposition using a shadowmask. All devices had a channel width (W) of 600 µm, while thechannel length L was varied.The effect of chemical doping was assessed using OFETs withgold source/drain electrodes. Fig. 2a-c show representativecharacteristics of our OFET with an undoped PTAA interlayer.The mobilities extracted from transfer characteristics wereµlin = 0.23 cm2 V−1 s−1 and µsat = 5.1 cm2 V−1 s−1 in the linearand saturation regimes, respectively. In the linear regime, alarge kink was observed in the current level as the gate voltage(VG) approached the threshold voltage (Vth)42. The outputcharacteristics exhibited S-shaped curves at low drain voltages(VD), indicating high contact resistances. Fig. 2d-f show the char-acteristics of an OFET with a doped PTAA interlayer. Comparedto the undoped case, mobilities were increased, reaching µlinof 4.8 cm2 V−1 s−1 and µsat of 9.2 cm2 V−1 s−1. We applied thetransfer length method (TLM) to evaluate the contact resistance(RC) using doped OFETs with channel lengths of 8, 24, 70,90, 110, 150, 175, and 190 µm (Fig. 2g). Fig. 2h shows thewidth-normalized total resistance (Rtotal ·W) as a function of L forvarious VG−Vth values. We estimated RC ·W and intrinsic mobility(µint) from the intercept and slope of this plot, respectively, andplotted it against VG−Vth in Fig. 2i. At the highest carrier density(VG −Vth = −21 V), RC ·W was estimated to be 930±130 Ωcm.These results suggest that doping the PTAA interlayer effectivelyreduces contact resistance in OFETs, enabling sufficiently lowRC values for high-mobility operation. While this value is notparticularly remarkable compared to conventional single-crystalOFETs with Au contact electrodes (typically less than ×103Ωcm)43, it is noteworthy in the context of Cu contact electrodes,as discussed in the following sections.We observed enhanced injection properties using doped in-terlayers even when copper contact electrodes were employed.Journal Name, [year], [vol.],1–7 | 31000080006000400020000RCW (Ω cm)-20 -16 -12 -8VG − Vth (V)121086420µint  (cm2 V−1 s−1)121086420RtotalW (x103  Ω cm)12080400L (μm)VG − Vth (V)−13−18−23-25-20-15-10-50I D (x10-6 A)-30-20-100VG (V)L (µm)VD = −1 V173783100120-300-200-1000100I D (x10-6 A)-30-20-100VD (V)10-810-710-610-510-410-3|I D| (A)-30-20-100VG (V)20151050|ID | 1/2 (x10-3 A1/2)10-910-810-710-610-510-4|I D| (A)-30-20-100VG (V)-20-15-10-50ID  (x10-6 A)1050-5-10I D (x10-6 A)-30-20-100VD (V)10-1110-1010-910-810-710-610-5|I D| (A)-30-20-100VG (V)43210|ID | 1/2 (x10-3 A1/2)10-1010-910-810-710-6|I D| (A)-30-20-100VG (V)-1.0-0.8-0.6-0.4-0.20.0ID  (x10-6 A)a b cCuCu /PTAA dopedVD = −1 V VD = −30 VVD = −1 V VD = −30 VΔVG = −5 Vd e fCu /PTAA dopedCuCu /PTAA dopedCuΔVG = −5 Vg h iCu /PTAA dopedCu /PTAA dopedCu /PTAA dopedFig. 3 Comparison of OFET characteristics using Cu electrodes with and without doped PTAA interlayer. Transfer curves in the (a) linear regime(VD at −1 V) and (b) saturation regime (VD at −30 V) and (c) the output characteristics of the OFET without PTAA interlayer. L is 84 µm. Transfercurves in the (d) linear regime (VD at −1 V) and (e) saturation regime (VD at −30 V) and (f) the output characteristics of the OFET with dopedPTAA interlayer. L is 83 µm. In (c) and (f), the employed VG values are −30 V, −25 V, −20 V, −15 V, −10 V, −5 V, 0 V, and 5 V. (g) Transfer curvesin the linear regime with different L in OFETs with the doped PTAA interlayer and (h) corresponding TLM plots at various VG −Vth. (i) Dependenceof RCW and µint on VG −Vth.Typically, copper electrodes have a WF of 4.6 eV24, which is in-adequate for effective hole injection into p-type OSCs with am-bient stability. Indeed, poor performance was observed in ourOFET when copper was directly deposited on C9–DNBDT–NW, asshown in Fig 3a-c. In this case, µlin was 9.4× 10−2 cm2 V−1 s−1and µsat was 2.0×10−1 cm2 V−1 s−1, which are lower than the in-trinsic mobility of C9–DNBDT–NW. In the linear regime, a dis-tinct kink was observed in the transfer curve. The output char-acteristics exhibited current saturation at low VD. These be-haviors suggest that transistor performance suffers significantlyfrom the large injection barrier between the copper electrodesand C9–DNBDT–NW layer. Assuming that contact limits the de-vice performance in the linear regime, RC ·W is approximately1.2 × 105 Ωcm. The device performance was significantly im-proved by stacking a doped PTAA interlayer between the copperelectrode and C9–DNBDT–NW layer, as shown in Fig. 3 d-f. Inthis configuration, we observed increases in µlin to 2.8 cm2 V−1 s−1and µsat to 5.0 cm2 V−1 s−1. Current saturation in the outputcharacteristics occurred when VD and VG approached each other,which is in agreement with the standard transistor operation.The on-off ratio of our device remained high at approximately104. Here, the PTAA layer contributes minimally to the off cur-rents, especially given the substantial mobility difference betweenPTAA (3 × 10−3 cm2 V−1 s−1)40 and C9–DNBDT–NW. While toohigh doping levels of the C9–DNBDT–NW channel would increasethe off currents, our doping process resulted in sufficiently lowdoping levels to maintain the on-off ratio, as discussed in detaillater. We applied the TLM method to evaluate the contact re-sistance of copper-based OFETs with the doped PTAA interlayer,similar to our assessment of gold electrodes. Fig. 3g and h showthe transfer curve in the linear region of the OFETs with varyingchannel lengths and the relationship between Rtotal ·W and L atvarious values of VG −Vth. The dependences of RC ·W and µint onVG −Vth are shown in Fig. 3i. At the maximum carrier density(VG −Vth =−23 V), RC ·W was estimated to be (2.8± 0.7)× 103Ωcm, which is, to the best of our knowledge, the lowest value4 | 1–7Journal Name, [year], [vol.],reported for copper-based OFETs operating in air. These findingsdemonstrate that our doped interlayer substantially enhances thecarrier injection properties, even when the electrodes have rela-tively low WFs.Photoelectron measurements of the doped PTAA layerTo clarify the structure and role of the PTAA layer, XPS and UPSmeasurements were performed. Fig. 4a shows the XPS surveyspectra of PTAA films. The pristine PTAA spectrum reveals peaksfor C 1s, N 1s, Au 4f, and O 1s. In contrast, the spectrum ofPTAA doped using an aqueous solution of BQ and Li-TFPB showsa new F 1s peak, confirming the incorporation of TFPB− into thePTAA film. Table 1 lists the relative quantitative analysis resultsfor each element detected from the narrow spectra (Fig. S2). Theratios of N and F indicate that TFPB− is present at approximatelyone TFPB−for every five PTAA monomers around the surface ofthe thin film based on the molecular structures of the anion andPTAA.Intensity (a.u.)2.0 1.0 0 -1.0Binding Energy (eV)VB edgeIntensity (a.u.)19 18 17 16 15Binding Energy (eV)SECOPTAA dopedPTAAIntensity (a.u.)1200 1000 800 600 400 200 0Binding Energy (eV)PTAA dopedPTAAF KLLF 1s C 1sAu 4fN 1sO 1sab cEFFig. 4 (a) X-ray photoelectron spectroscopy survey spectrum of thin filmsof undoped and doped PTAA. KLL shows peaks originating from KLLAuger transitions. UPS spectra of the region of (b) secondary electroncutoff (SECO) and (c) the edge of HOMO density of states for undopedand doped PTAA thin films. (The binding energy of the Fermi level isaligned to 0 eV.)Table 1 Relative atomic concentrations (%) of elements detected in thephotoelectron escape depth range in PTAA thin films before and afterdoping.sample C N F Au OPTAA (pristine) 69.4 3.9 - 2.1 1.4PTAA (doped) 80.1 3.4 13.7 0.2 2.6Fig. 4b and c show the UPS spectra of undoped and dopedPTAA thin films. The origin of the binding energy aligns with theFermi energy (EF) as determined by the Fermi edge observed in agold electrode. Based on the position of secondary electron cut-off (SECO), WF of PTAA thin films were determined to be 4.3 eVand 5.0 eV, respectively. The increased WF after the treatmentwith solutions containing BQ and Li-TFPB indicates effective dop-ing, which is consistent with the reported oxidation capability ofBQ39. Notably, after the doping process, the edge of the HOMOdensity of states was close to EF.Considering that semiconductor doping levels significantly in-fluence injection barriers at metal/semiconductor interfaces, ourdoping process reduces the barrier height between the copperelectrodes and PTAA layers. Although high doping levels canlower this barrier height, excessive doping in the PTAA layerin contact with the C9–DNBDT–NW active layer could hindernormally-off operation. Here, a WF of 5.0 eV in the PTAA layermay not result in the excessive doping of C9–DNBDT–NW withan ionization potential of 5.24 eV14. Thus, our doping processachieves a balance between injection properties from copper elec-trodes and the normally-off operation of our OFETs. In Fig. 3b,the current in the subthreshold region begins to rise from aroundVG of 0 V, supporting the conclusion that the Fermi energy is closeto optimal. This interpretation is consistent with previous reportsshowing that the onset voltage shifts with doping level in sim-ilar configurations44. Adjusting the WF is necessary dependingon the interlayer and active layer choice. Using aqueous solu-tions for chemical doping simplifies WF control through pH ad-justments39. Considering that doped PTAA has been used as ahole-transporting layer in perovskite solar cells45, this strategymay be applicable to a broad range of p-type semiconductors andrelated devices.ConclusionThis paper presents a novel approach for fabricating high-performance electronic devices using extended choice for elec-trode materials. The PTAA interlayer was stacked between cop-per electrodes and thin-film single crystals of C9–DNBDT–NW,which was chemically doped using aqueous doping solutions. Theemployment of doped interlayer enhanced hole injection prop-erties and mobility in p-type OFETs. A contact resistance of2.8 × 103 Ωcm and µsat of 5.0 cm2 V−1 s−1 were observed, indi-cating significant improvements over conventional devices usingcopper electrodes. The shallow yet effective chemical doping suc-cessfully reduces the injection barrier from the copper electrodeswhile maintaining high on-off ratios. These findings can advanceOSC-based devices by expanding material selection, thus enhanc-ing cost efficiency and environmental sustainability.MethodsSC-OSC FabricationAn n-type doped silicon substrate with a 100 nm SiO2layer was treated with a self-assembled monolayer of 2-(phenylhexyl)trimethoxysilane. SCs of C9–DNBDT–NW werefabricated from a 0.02 wt% 3-chlorothiophene solution usingthe continuous edge-casting method15. During this process, thesubstrate temperature was precisely controlled to obtain the SCdomain within the monolayer.Journal Name, [year], [vol.],1–7 | 5Interlayer FabricationAn EAGLE XG glass substrate (Corning Inc.) was treatedwith UV/O3 for 15 min to enhance its hydrophilic-ity. The polymer interlayers, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine](PTAA) (Solaris Chem Inc.), weredissolved in toluene at a concentration of 0.2 wt% and spin-coated onto the UV/O3 treated glass substrates. These PTAAthin films were placed directly above the C9–DNBDT–NW layers.The PTAA interlayers were fabricated by peeling them off thehydrophilic glass substrate using deionized water followed byannealing at 80 ◦C under vacuum to remove the solvent.Interlayer Doping and SC-OFET FabricationTo dope the interlayers, we immersed them in aqueous dopantsolutions under ambient conditions. The doping solutions wereprepared by dissolving 10 mM BQ and 10 mM lithium TFPB ina pH= 2.0 aqueous solution. After immersion, the interlayerswere washed with deionized water, and the residual solvent wasremoved using an N2 flow.Au was deposited using a metal mask to create the source/drainelectrodes. C9–DNBDT–NW and PTAA layers were patterned viadry-etching with a yttrium-aluminum-garnet laser (266 nm).Electrical MeasurementElectrical measurements were performed using a semiconductorparameter analyzer (Keithley 4200-SCS) in the dark under ambi-ent conditions. The mobilities in the linear (µlin) and saturation(µsat) regimes were extracted from the transfer characteristicsusing the following equations:ID,lin = µlinWCiL(VG −Vth)VDID,sat = µsatWCi2L(VG −Vth)2where ID, L, W , Ci, VG, Vth, and VDare the drain current,channel length, channel width, capacitance per unit area,gate voltage, threshold voltage, and drain voltage, respectively.Ci =34.5 nFcm−2 was used for all devices.XPS and UPS AnalysisXPS and UPS experiments were performed using a KRATOSULTRA 2 instrument. XPS employed monochromatic Al KαX-rays for a wide scan from 0 to 1200 eV. For UPS, we utilizedphotons at 21.2 eV from a He discharge lamp. The bindingenergies in the UPS experiments were calibrated using the Fermiedge of the metal substrates. A bias voltage of −8.0 V wasapplied to the sample during UPS measurements.Author ContributionsA.M. fabricated and evaluated the transistors. Y.Y. contributedto the conceptualization of this work. T. S. contributed to theevaluation of the transistors. M.I. contributed to the developmentof the doping process. S.W. and J.T. supervised the study. A. M.and Y. Y. wrote the manuscript.Conflicts of interestThe authors declare no conflict of interest.Data availabilityThe data supporting this work are available in the main text andSupplementary Information.AcknowledgmentsThis work was supported in part by JST CREST (JPMJCR21O3),JST FOREST (JPMJFR236R), and JSPS KAKENHI grants(JP23K23428 and JP22H04959).Notes and references1 A. Nawaz, L. Merces, L. M. 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