Thermal Annealing-modulated Ion Doping and Synaptic Behavior of Organic Electrochemical Transistors Based on Block Copolymers

Abstract

Organic electrochemical transistors (OECTs) garner significant attention in biosensing and neuromorphic computing applications owing to their high transconductance, low operating voltage, and biocompatibility. Among the various factors influencing OECTs performance and functionality, particularly synaptic behavior emulation, ion doping/dedoping kinetics play a pivotal role. However, precise control of ion dynamics remains challenging because of the complex interplay between material properties and microstructural characteristics. In this study, we demonstrate the modulation of the ion doping dynamics and synaptic behavior of OECTs based on hydrophilic-hydrophobic block copolymers (DPP-b-g2T-T) through thermal annealing. We investigate the correlations among segmental hydrophilicity/hydrophobicity, crystallinity, and ion transport kinetics. Our findings reveal that hydrophilic g2T-T segments enhance the ion doping efficiency, whereas hydrophobic DPP segments restrict ion transport. Thermal annealing reduces the ion doping/dedoping rates for both segments, particularly Au-gated OECTs. This phenomenon is attributed to the enhanced film crystallinity, which impedes ion transport, especially under the relatively weak gate control effect characteristic of Au. Leveraging the annealing-modulated ion doping/dedoping dynamics and prolonged retention time, we emulate short-term plasticity (STP) and long-term plasticity (LTP). This work establishes a strategy for optimizing OECTs synaptic performance through synergistic molecular design and thermal annealing, contributing to the advancement of neuromorphic technology.

Keywords

Organic electrochemical transistor / Hydrophilichydrophobic block copolymer / Thermal annealing / Ion transport dynamics / Synaptic plasticity

References

[1] GaoC, LiuD, XuC, BaiJ, LiE, ZhangX, ZhuX, HuY, LinZ, GuoT, ChenHAdv. Funct. Mater., 2024, 342001864

[2] ParkH L, LeeT WOrg. Electron., 2021, 98106301.

[3] SunJ, FuY, WanQJ. Phys. D: Appl. Phys., 2018, 51314004.

[4] JiangX, WangQ, WangZ, DongB, HuangL, ChiLChem. Res. Chinese Universities, 2021, 37975.

[5] FriedleinJ T, McLeodR R, RivnayJOrg. Electron., 2018, 63398.

[6] RivnayJ, InalS, SalleoA, OwensR M, BerggrenM, MalliarasG GNat. Rev. Mater., 2018, 317086.

[7] GuoJ, ChenS E, GiridharagopalR, BischakC G, OnoratoJ W, YanK, ShenZ, LiC Z, LuscombeC K, GingerD SNat. Mater., 2024, 23656.

[8] ShameemR, BongartzL M, WeissbachA, KleemannH, LeoKAppl. Sci., 2023, 135754.

[9] ZhaoC, YangJ, MaWNanomicro Lett., 2024, 16233

[10] HuangW, ChenJ, YaoY, ZhengD, JiX, FengL W, MooreD, GlavinN R, XieM, ChenY, PankowR M, SurendranA, WangZ, XiaY, BaiL, RivnayJ, PingJ, GuoX, ChengY, MarksT JFacchetti A., Nature, 2023, 613496

[11] JeongS Y, MoonJ W, LeeS, WuZ, ParkS H, ChoJ H, WooH YAdv. Electron. Mater., 2023, 92300053.

[12] BakryA, YadavP, ChenS E, LuscombeC KFaraday Discuss., 2024, 25074.

[13] BischakC G, FlaggL Q, GingerD SAdv. Mater., 2020, 32e2002610.

[14] KimN, GoG T, ParkH L, AhnY, KimJ, LeeY, SeoD G, LeeW, KimY H, YangH, LeeT WAdv. Intell. Syst., 2023, 52300016.

[15] SamalS, RohH, CuninC E, YangG G, GumyusengeASmall, 2023, 19e2207554.

[16] WuR, XieM, ChengY, ZhaoD, FengL, ChenJ, HuangWJ. Mater. Chem. C, 2025, 13821.

[17] InalS, RivnayJ, LeleuxP, FerroM, RamuzM, BrendelJ C, SchmidtM M, ThelakkatM, MalliarasG GAdv. Mater., 2014, 267450.

[18] JiX, PaulsenB D, ChikG K K, WuR, YinY, ChanP K L, RivnayJNat. Commun., 2021, 122480.

[19] KimD H, LeeJ, KimY, YooH, LeeE KOrg. Electron., 2024, 131107076.

[20] FlaggL Q, BischakC G, OnoratoJ W, RashidR B, LuscombeC K, GingerD SJ. Am. Chem. Soc., 2019, 1414345.

[21] Hidalgo CastilloT C, ShanW, MaG, ZhaoH, WangY, DruetV, SalehA, GuX, InalSAdv. Mater., 2025, 37e2411214.

[22] SeoD G, LeeY, GoG T, PeiM, JungS, JeongY H, LeeW, ParkH L, KimS W, YangH, YangC, LeeT WNano Energy, 2019, 65104035.

[23] ZhouZ, WuX, TamT L D, TangC G, ChenS, HouK, LiT, HeQ, SitJ J, XuJ, LeongW LAdv. Funct. Mater., 2023, 342305780.

[24] GoG T, LeeY, SeoD G, PeiM, LeeW, YangH, LeeT WAdv. Intell. Syst., 2020, 22000012.

[25] BilkayT, SchulzeK, Egorov-BreningT, BohnA, JanietzSMacromol. Chem. Phys., 2012, 2131970.

[26] LuoH, YuC, LiuZ, ZhangG, GengH, YiY, BrochK, HuY, SadhanalaA, JiangL, QiP, CaiZ, SirringhausH, ZhangDSci. Adv., 2016, 2e1600076.

[27] WangQ, XiangC, JiangX, ShiC, WangZ, HuangL, ChiLJ. Phys. Chem. Lett., 2024, 157175.

[28] MoserM, SavagianL R, SavvaA, MattaM, PonderJ F, HidalgoT C, OhayonD, HallaniR, ReisjalaliM, TroisiA, WadsworthA, ReynoldsJ R, InalS, McCullochIChem. Mater., 2020, 326618.

[29] NielsenC B, GiovannittiA, SbirceaD T, BandielloE, NiaziM R, HanifiD A, SessoloM, AmassianA, MalliarasG G, RivnayJ, McCullochIJ. Am. Chem. Soc., 2016, 13810252.

[30] LiH, JinZ, JiangX, AnM, JiJ, HuangDAppl. Phys. Lett., 2024, 124093509.

[31] JiJ, LiuJ, WangY, ZhangF, ZhaoM, YanS, GuoX, ZhangW, SangS, ChaiX, SunQ NEnergy, 2024, 128109962

[32] WangS, ChenX, ZhaoC, KongY, LinB, WuY, BiZ, XuanZ, LiT, LiY, ZhangW, MaE, WangZ, MaWNat. Electron., 2023, 6281.

[33] AnderssonL, SprikM, HutterJ, ZhangCAngew. Chem. Int. Ed., 2025, 64e202413614.

[34] BisquertJ, TesslerNAdv. Funct. Mater., 2024, 352419000.

[35] BernardsD, MalliarasGAdv. Funct. Mater., 2007, 173538.

[36] ChenF, ZhouY, ZhuY, ZhuR, GuanP, FanJ, ZhouL, ValanoorN, FredericW, SaribatirE, BirznieksI, WanT, ChuDJ. Mater. Chem. C, 2021, 98372.

[37] PanX, JinT, GaoJ, HanC, ShiY, ChenWSmall, 2020, 16e2001504.

[38] HuS G, LiuY, ChenT P, LiuZ, YuQ, DengL J, YinY, HosakaSAppl. Phys. Lett., 2013, 103133701.

[39] ZuckerR S, RegehrW GAnnu. Rev. Physiol., 2002, 64355.

[40] ZhaoY, SuC, ShenG, XieZ, XiaoW, FuY, InalS, WangQ, WangY, YueW, McCullochI, HeDAdv. Funct. Mater., 2022, 322205744.

[41] HarikeshP C, YangC Y, WuH Y, ZhangS, DonahueM J, CaravacaA S, HuangJ D, OlofssonP S, BerggrenM, TuD, FabianoSNat. Mater., 2023, 22242.

[42] ChouhdryH H, LeeD H, BagA, LeeN ENat. Commun., 2023, 14821.

RIGHTS & PERMISSIONS

Jilin University, The Editorial Department of Chemical Research in Chinese Universities and Springer-Verlag GmbH