Issue

Vol. 18 (2026)

A Review on Multi-Level Asymmetric Design for 2D Neuromorphic Devices

https://doi.org/10.1007/s40820-026-02214-8
Yilin Sun
School of Microelectronics Science and Technology, Sun Yat-sen University, Zhuhai 519000, Guangdong, People’s Republic of China
Yuandong Gao
School of Microelectronics Science and Technology, Sun Yat-sen University, Zhuhai 519000, Guangdong, People’s Republic of China
Zimu Wang
School of Microelectronics Science and Technology, Sun Yat-sen University, Zhuhai 519000, Guangdong, People’s Republic of China
Zerui Cai
School of Microelectronics Science and Technology, Sun Yat-sen University, Zhuhai 519000, Guangdong, People’s Republic of China
Zhifang Liu
Institute of Atomic Manufacturing, International Institute for Interdisciplinary and Frontiers, Beihang University, Beijing 100191, People’s Republic of China
Jianlong Xu
Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon‑Based Functional Materials & Devices, Soochow University, Suzhou 215123, Jiangsu, People’s Republic of China

Corresponding Author: Jianlong Xu

xujianlong@suda.edu.cn

Nano-Micro Letters, Vol. 18 (2026), Article Number: 354

Abstract

Asymmetry has emerged as a critical design strategy for implementing essential neuromorphic functionalities, such as directional signal propagation, programmable plasticity, and bio-inspired dynamics. This principle involves deliberately breaking symmetry at various scales, which introduces unique physical phenomena including spontaneous built-in fields, anisotropic carrier transport, and memristive switching, which are foundational to synaptic and neuronal emulation. Despite growing research, a systematic synthesis of how asymmetry function across different design levels is lacking, hindering the development of guiding design principles. This review bridges this gap by systematically examining asymmetric engineering across three levels: materials, structures, and device. Benefiting from the inherent structural and electronic versatility of two-dimensional (2D) materials, their unique physical properties arising from such multi-level asymmetry for emulating and regulating synaptic plasticity are analyzed to demonstrate the resultant functional diversity and tunability of neuromorphic devices. Furthermore, existing challenges are discussed and a forward-looking perspective on integrating multiple asymmetries and extending the concept to circuit and system levels is provided. This work aims to establish a coherent design framework and provide a unique pathway for developing next-generation neuromorphic intelligent hardware based on 2D materials.


Highlights:
1 This review highlights the pivotal role of asymmetry as a core design strategy for realizing key neuromorphic functionalities by breaking symmetry across scales to induce unique physical phenomena.
2 It systematically synthesizes asymmetric engineering at materials, structures, and device levels, with a focus on 2D materials to elaborate how their multi-level asymmetry enables tunable synaptic plasticity emulation.
3 It addresses existing research gaps, discusses current challenges, and provides a forward-looking perspective to establish a coherent design framework for next-generation 2D material-based neuromorphic hardware.

Keywords

Asymmetric design Anisotropic crystal structure Band alignment engineering Contact engineering Neuromorphic devices
Sun, Yilin, Yuandong Gao, Zimu Wang, Zerui Cai, Zhifang Liu, and Jianlong Xu. 2026. “A Review on Multi-Level Asymmetric Design for 2D Neuromorphic Devices”. Nano-Micro Letters 18 (May):354. https://doi.org/10.1007/s40820-026-02214-8.
Download Citation
Endnote/Zotero/Mendeley (RIS)
BibTeX
References
  1. S. Wang, M. Wu, W. Liu, J. Liu, Y. Tian et al., Dopamine detection and integration in neuromorphic devices for applications in artificial intelligence. Device 2(2), 100284 (2024). https://doi.org/10.1016/j.device.2024.100284
  2. J. Yao, Y. Teng, Q. Wang, Y. He, L. Liu et al., Advancing intelligent neuromorphic computing: recent progress in all-optical-controlled artificial synaptic devices. ACS Nano 19(29), 26320–26346 (2025). https://doi.org/10.1021/acsnano.5c05240
  3. M.H. Pervez, E. Elahi, M.A. Khan, M. Nasim, M. Asim et al., Recent developments on novel 2D materials for emerging neuromorphic computing devices. Small Struct. 6(2), 2400386 (2025). https://doi.org/10.1002/sstr.202400386
  4. V. Milo, G. Malavena, C. Monzio Compagnoni, D. Ielmini, Memristive and CMOS devices for neuromorphic computing. Materials 13(1), 166 (2020). https://doi.org/10.3390/ma13010166
  5. Y. Sun, Y. Ding, D. Xie, Mixed-dimensional van der Waals heterostructures enabled optoelectronic synaptic devices for neuromorphic applications. Adv. Funct. Mater. 31(47), 2105625 (2021). https://doi.org/10.1002/adfm.202105625
  6. Q. He, H. Wang, Y. Zhang, A. Chen, Y. Fu et al., Two-dimensional materials based two-transistor-two-resistor synaptic kernel for efficient neuromorphic computing. Nat. Commun. 16, 4340 (2025). https://doi.org/10.1038/s41467-025-59815-x
  7. T.C. Südhof, Neurotransmitter release: the last millisecond in the life of a synaptic vesicle. Neuron 80(3), 675–690 (2013). https://doi.org/10.1016/j.neuron.2013.10.022
  8. R.A. Nicoll, A brief history of long-term potentiation. Neuron 93(2), 281–290 (2017). https://doi.org/10.1016/j.neuron.2016.12.015
  9. X. Li, H. Liu, C. Ke, W. Tang, M. Liu et al., Review of anisotropic 2D materials: controlled growth, optical anisotropy modulation, and photonic applications. Laser Photonics Rev. 15(12), 2100322 (2021). https://doi.org/10.1002/lpor.202100322
  10. Z. Yang, Z. Yang, L. Liu, X. Li, J. Li et al., Anisotropic mass transport enables distinct synaptic behaviors on 2D material surface. Mater. Today Electron. 5, 100047 (2023). https://doi.org/10.1016/j.mtelec.2023.100047
  11. Y. Zhu, Y. Tao, Z. Wang, J. Bian, Z. Li et al., In-plane anisotropic two-dimensional ReSe2 optoelectronic memristor for a polarization-sensitive neuromorphic vision system. ACS Nano 19(27), 25480–25489 (2025). https://doi.org/10.1021/acsnano.5c08221
  12. R.K. Pandey, S. Baek, N. Lee, S.-M. Lee, S. Lee, Asymmetric contact van der Waals ferroelectric transistors for self-powered multifunctional artificial visual system. ACS Nano 19(39), 35071–35080 (2025). https://doi.org/10.1021/acsnano.5c12376
  13. A.N. Rudenko, M.I. Katsnelson, Anisotropic effects in two-dimensional materials. 2D Mater. 11(4), 042002 (2024). https://doi.org/10.1088/2053-1583/ad64e1
  14. W. Ahmad, Y. Wang, J. Kazmi, U. Younis, N.M. Mubarak et al., Janus 2D transition metal dichalcogenides: research progress, optical mechanism and future prospects for optoelectronic devices. Laser Photonics Rev. 19(6), 2400341 (2025). https://doi.org/10.1002/lpor.202400341
  15. Y.-F. Zhang, H. Guo, Y. Zhu, S. Song, X. Zhang et al., Emerging multifunctionality in 2D ferroelectrics: a theoretical review of the interplay with magnetics, valleytronics, mechanics, and optics. Adv. Funct. Mater. 34(51), 2410240 (2024). https://doi.org/10.1002/adfm.202410240
  16. C. Chen, Y. Zhou, L. Tong, Y. Pang, J. Xu, Emerging 2D ferroelectric devices for in-sensor and in-memory computing. Adv. Mater. 37(2), 2400332 (2025). https://doi.org/10.1002/adma.202400332
  17. H. Wang, Z. Liu, Y. Sun, X. Ping, J. Xu et al., Anisotropic electrical properties of aligned PtSe2 nanoribbon arrays grown by a pre-patterned selective selenization process. Nano Res. 15(5), 4668–4676 (2022). https://doi.org/10.1007/s12274-022-4110-3
  18. C. Wang, G. Zhang, S. Huang, Y. Xie, H. Yan, The optical properties and plasmonics of anisotropic 2D materials. Adv. Opt. Mater. 8(5), 1900996 (2020). https://doi.org/10.1002/adom.201900996
  19. J. Yang, C. Liu, H. Xie, W. Yu, Anisotropic heat transfer properties of two-dimensional materials. Nanotechnology 32(16), 162001 (2021). https://doi.org/10.1088/1361-6528/abdb15
  20. Z.-D. Gao, Z.-H.-Y. Jiang, J.-D. Li, B.-W. Li, Y.-Y. Long et al., Anisotropic mechanics of 2D materials. Adv. Eng. Mater. 24(11), 2200519 (2022). https://doi.org/10.1002/adem.202200519
  21. J. He, D. He, Y. Wang, Q. Cui, M.Z. Bellus et al., Exceptional and anisotropic transport properties of photocarriers in black phosphorus. ACS Nano 9(6), 6436–6442 (2015). https://doi.org/10.1021/acsnano.5b02104
  22. P.K. Venuthurumilli, P.D. Ye, X. Xu, Plasmonic resonance enhanced polarization-sensitive photodetection by black phosphorus in near infrared. ACS Nano 12(5), 4861–4867 (2018). https://doi.org/10.1021/acsnano.8b01660
  23. Z. Luo, J. Maassen, Y. Deng, Y. Du, R.P. Garrelts et al., Anisotropic in-plane thermal conductivity observed in few-layer black phosphorus. Nat. Commun. 6, 8572 (2015). https://doi.org/10.1038/ncomms9572
  24. J. Tao, W. Shen, S. Wu, L. Liu, Z. Feng et al., Mechanical and electrical anisotropy of few-layer black phosphorus. ACS Nano 9(11), 11362–11370 (2015). https://doi.org/10.1021/acsnano.5b05151
  25. H. Liu, C. Zhu, Y. Chen, X. Yi, X. Sun et al., Polarization-sensitive photodetectors based on highly in-plane anisotropic violet phosphorus with large dichroic ratio. Adv. Funct. Mater. 34(17), 2314838 (2024). https://doi.org/10.1002/adfm.202314838
  26. D. Lu, J. Tan, M. Zhang, M. Shi, X. Feng et al., Probing the temperature-dependent thermal conductivity of violet phosphorus via optothermal Raman spectroscopy. J. Phys. Chem. Lett. 15(35), 8942–8948 (2024). https://doi.org/10.1021/acs.jpclett.4c02000
  27. J. Singh, M. Jakhar, A. Kumar, K. Tankeshwar, Anisotropic and high carrier mobility of 2D α-te. Dae Solid State Physics Symposium 2019 Jodhpur, India. AIP Publishing, (2020): 030693. https://doi.org/10.1063/5.0017367
  28. J. Zhang, J. Liu, Y. Tian, J. Guo, W. Kong et al., Polarization-sensitive and wide-spectrum photodetector from ultraviolet to near-infrared light based on 2D tellurium at room temperature. Appl. Surf. Sci. 670, 160685 (2024). https://doi.org/10.1016/j.apsusc.2024.160685
  29. S. Huang, M. Segovia, X. Yang, Y.R. Koh, Y. Wang et al., Anisotropic thermal conductivity in 2D tellurium. 2D Mater. 7(1), 015008 (2020). https://doi.org/10.1088/2053-1583/ab4eee
  30. H. Ma, W. Hu, J. Yang, Control of highly anisotropic electrical conductance of tellurene by strain-engineering. Nanoscale 11(45), 21775–21781 (2019). https://doi.org/10.1039/c9nr05660b
  31. F. Chu, M. Chen, Y. Wang, Y. Xie, B. Liu et al., A highly polarization sensitive antimonene photodetector with a broadband photoresponse and strong anisotropy. J. Mater. Chem. C 6(10), 2509–2514 (2018). https://doi.org/10.1039/C7TC05488B
  32. G. Liu, H. Wang, G.-L. Li, D. Wang, Giant anisotropy of thermal expansion and thermomechanical properties of monolayer α-antimonene: A first-principles study. Comput. Mater. Sci. 169, 109132 (2019). https://doi.org/10.1016/j.commatsci.2019.109132
  33. L. Pi, C. Hu, W. Shen, L. Li, P. Luo et al., Highly in-plane anisotropic 2D PdSe2 for polarized photodetection with orientation selectivity. Adv. Funct. Mater. 31(3), 2006774 (2021). https://doi.org/10.1002/adfm.202006774
  34. L. Chen, W. Zhang, H. Zhang, J. Chen, C. Tan et al., In-plane anisotropic thermal conductivity of low-symmetry PdSe2. Sustainability 13(8), 4155 (2021). https://doi.org/10.3390/su13084155
  35. C. Long, Y. Liang, H. Jin, B. Huang, Y. Dai, PdSe2: flexible two-dimensional transition metal dichalcogenides monolayer for water splitting photocatalyst with extremely low recombination rate. ACS Appl. Energy Mater. 2(1), 513–520 (2019). https://doi.org/10.1021/acsaem.8b01521
  36. R. Wang, X. Xu, Y. Yu, M. Ran, Q. Zhang et al., The mechanism of the modulation of electronic anisotropy in two-dimensional ReS2. Nanoscale 12(16), 8915–8921 (2020). https://doi.org/10.1039/D0NR00518E
  37. F. Liu, S. Zheng, X. He, A. Chaturvedi, J. He et al., Highly sensitive detection of polarized light using anisotropic 2D ReS2. Adv. Funct. Mater. 26(8), 1169–1177 (2016). https://doi.org/10.1002/adfm.201504546
  38. Y.-D. Cao, Y.-H. Sun, S.-F. Shi, R.-M. Wang, Anisotropy of two-dimensional ReS2 and advances in its device application. Rare Met. 40(12), 3357–3374 (2021). https://doi.org/10.1007/s12598-021-01781-6
  39. W.-L. Tao, Y.-Q. Zhao, Z.-Y. Zeng, X.-R. Chen, H.-Y. Geng, Anisotropic thermoelectric materials: pentagonal PtM2 (M = S, Se, Te). ACS Appl. Mater. Interfaces 13(7), 8700–8709 (2021). https://doi.org/10.1021/acsami.0c19460
  40. J. Guo, Y. Liu, Y. Ma, E. Zhu, S. Lee et al., Few-layer GeAs field-effect transistors and infrared photodetectors. Adv. Mater. 30(21), e1705934 (2018). https://doi.org/10.1002/adma.201705934
  41. Z. Zhou, M. Long, L. Pan, X. Wang, M. Zhong et al., Perpendicular optical reversal of the linear dichroism and polarized photodetection in 2D GeAs. ACS Nano 12(12), 12416–12423 (2018). https://doi.org/10.1021/acsnano.8b06629
  42. X. Jiang, T. Zhao, D. Wang, Anisotropic ductility and thermoelectricity of van der Waals GeAs. Phys. Chem. Chem. Phys. 25(40), 27542–27552 (2023). https://doi.org/10.1039/d3cp03119e
  43. R. Lu, Y. Li, H. Song, J. Jiang, Recent advances in emerging polarization-sensitive materials: from linear/circular polarization detection to neuromorphic device applications. Adv. Funct. Mater. 35(24), 2423770 (2025). https://doi.org/10.1002/adfm.202423770
  44. R. Khan, N.U. Rehman, S. Kalluri, S. Elumalai, A. Saritha et al., 2D MoTe2 memristors for energy-efficient artificial synapses and neuromorphic applications. Nanoscale 17(21), 13174–13206 (2025). https://doi.org/10.1039/d5nr01509j
  45. D. Xie, K. Yin, Z.-J. Yang, H. Huang, X. Li et al., Polarization-perceptual anisotropic two-dimensional ReS2 neuro-transistor with reconfigurable neuromorphic vision. Mater. Horiz. 9(5), 1448–1459 (2022). https://doi.org/10.1039/d1mh02036f
  46. G. Peng, C. Zhang, M. Li, J. Zhang, C. Wu et al., Polarization-sensitive photodetectors based on anisotropic 2D selenium and its multifunctional applications. ACS Appl. Mater. Interfaces 17(39), 55074–55083 (2025). https://doi.org/10.1021/acsami.5c14109
  47. X. Zheng, Y. Zhou, Y. Guo, Symmetry manipulation of two-dimensional semiconductors by Janus structure. Acc. Mater. Res. 6(2), 124–128 (2025). https://doi.org/10.1021/accountsmr.4c00236
  48. R. Chaurasiya, S. Tyagi, A.J. Kale, G.K. Gupta, R. Kumar et al., Advances in physics and chemistry of transition metal dichalcogenide Janus monolayers: properties, applications, and future prospects. Adv. Theory Simul. 8(4), 2400854 (2025). https://doi.org/10.1002/adts.202400854
  49. R. Jana, S. Ghosh, R. Bhunia, A. Chowdhury, Recent developments in the state-of-the-art optoelectronic synaptic devices based on 2D materials: a review. J. Mater. Chem. C 12(15), 5299–5338 (2024). https://doi.org/10.1039/D4TC00371C
  50. J. Meng, T. Wang, H. Zhu, L. Ji, W. Bao et al., Integrated in-sensor computing optoelectronic device for environment-adaptable artificial retina perception application. Nano Lett. 22(1), 81–89 (2022). https://doi.org/10.1021/acs.nanolett.1c03240
  51. Y. Wang, B. Han, M. Mayor, P. Samorì, Opto-electrochemical synaptic memory in supramolecularly engineered Janus 2D MoS2. Adv. Mater. 36(8), e2307359 (2024). https://doi.org/10.1002/adma.202307359
  52. H. Zhu, T. Li, L. Fu, J. Bai, S. Li et al., A proprioceptive Janus fiber with controllable multistage segments for bionic soft robots. ACS Nano 18(46), 32023–32037 (2024). https://doi.org/10.1021/acsnano.4c10117
  53. X. Wang, Y. Sun, F. Liu, R. Zhang, T. Wang et al., Hierarchically engineered Janus fiber-hydrogel architecture: an ultrathin biomimetic skin for multiple-response sensing. Chem. Eng. J. 522, 168206 (2025). https://doi.org/10.1016/j.cej.2025.168206
  54. C. Wang, L. You, D. Cobden, J. Wang, Towards two-dimensional van der Waals ferroelectrics. Nat. Mater. 22(5), 542–552 (2023). https://doi.org/10.1038/s41563-022-01422-y
  55. K. Yang, H. Wan, J. Yu, H. Fu, J. Zhang et al., Interfacial polarization enhanced ultrafast carrier dynamics in ferroelectric CuInP2S6. Nano Lett. 25(5), 1890–1897 (2025). https://doi.org/10.1021/acs.nanolett.4c05369
  56. Q. He, Z. Tang, M. Dai, H. Shan, H. Yang et al., Epitaxial growth of large area two-dimensional ferroelectric α-In2Se3. Nano Lett. 23(7), 3098–3105 (2023). https://doi.org/10.1021/acs.nanolett.2c04289
  57. Y. Liu, W. Tang, J. Zeng, C. Bai, K. Zhou et al., Ferroelectric-based neuromorphic memory devices for bio-inspired computing. Nat. Rev. Electr. Eng. 2(11), 773–787 (2025). https://doi.org/10.1038/s44287-025-00222-1
  58. S. Baek, Y.K. Kim, S.-M. Lee, H. Choi, J.-S. Park et al., Steep-slope CuInP2S6 ferroionic threshold switching field-effect transistor for implementation of artificial spiking neuron. Adv. Mater. 37(44), e06921 (2025). https://doi.org/10.1002/adma.202506921
  59. Z. Wang, F. Li, Y. Zhao, Z. Wang, Y. Zhang et al., Artificial synapses based on CIPS/Te vdW heterojunction ferroelectric transistor for traffic light recognition. Appl. Phys. Lett. 126(21), 213501 (2025). https://doi.org/10.1063/5.0256495
  60. M. Li, Y. He, C. Wang, W.F. Io, F. Guo et al., Memristors based on ferroelectric Cu-deficient copper indium thiophosphate for multilevel storage and neuromorphic computing. Small 2412314 (2025). https://doi.org/10.1002/smll.202412314
  61. J. Niu, J. Lyu, J. Li, K.S. Samantaray, C. Jang et al., All-optical control of bidirectional polarization switching in ferroelectric heterostructures for neuromorphic and in-memory computing. Adv. Sci. (2026). https://doi.org/10.1002/advs.202522092
  62. S.-J. Kang, W. Jung, O.H. Gwon, H.S. Kim, H.R. Byun et al., Photo-assisted ferroelectric domain control for α-In2Se3 artificial synapses inspired by spontaneous internal electric fields. Small 20(22), 2470174 (2024). https://doi.org/10.1002/smll.202470174
  63. J. Zhou, A. Chen, Y. Zhang, D. Pu, B. Qiao et al., 2D ferroionics: conductive switching mechanisms and transition boundaries in van der Waals layered material CuInP2S6. Adv. Mater. 35(38), 2302419 (2023). https://doi.org/10.1002/adma.202302419
  64. L. You, F. Liu, H. Li, Y. Hu, S. Zhou et al., In-plane ferroelectricity in thin flakes of van der Waals hybrid perovskite. Adv. Mater. 30(51), 1803249 (2018). https://doi.org/10.1002/adma.201803249
  65. X. Wang, K. Yasuda, Y. Zhang, S. Liu, K. Watanabe et al., Interfacial ferroelectricity in rhombohedral-stacked bilayer transition metal dichalcogenides. Nat. Nanotechnol. 17(4), 367–371 (2022). https://doi.org/10.1038/s41565-021-01059-z
  66. S. Son, Y. Lee, J.H. Kim, B.H. Kim, C. Kim et al., Multiferroic-enabled magnetic-excitons in 2D quantum-entangled van der Waals antiferromagnet NiI2. Adv. Mater. 34(10), 2109144 (2022). https://doi.org/10.1002/adma.202109144
  67. R. Bian, C. Li, Q. Liu, G. Cao, Q. Fu et al., Recent progress in the synthesis of novel two-dimensional van der Waals materials. Natl. Sci. Rev. 9(5), nwab164 (2021). https://doi.org/10.1093/nsr/nwab164
  68. J. Xu, H. Che, C. Tang, B. Liu, Y. Ao, Tandem fields facilitating directional carrier migration in van der Waals heterojunction for efficient overall piezo-synthesis of H2O2. Adv. Mater. 36(32), 2404539 (2024). https://doi.org/10.1002/adma.202404539
  69. F. Zhang, H. Shi, Y. Yu, S. Liu, D. Liu et al., Dynamic band-alignment modulation in MoTe2/SnSe2 heterostructure for high performance photodetector. Adv. Opt. Mater. 12(16), 2303088 (2024). https://doi.org/10.1002/adom.202303088
  70. Z. Zhang, D. Yang, H. Li, C. Li, Z. Wang et al., 2D materials and van der Waals heterojunctions for neuromorphic computing. Neuromorph. Comput. Eng. 2(3), 032004 (2022). https://doi.org/10.1088/2634-4386/ac8a6a
  71. D. Jariwala, T.J. Marks, M.C. Hersam, Mixed-dimensional van der Waals heterostructures. Nat. Mater. 16(2), 170–181 (2017). https://doi.org/10.1038/nmat4703
  72. T. Zhao, W. Yue, Q. Deng, W. Chen, C. Luo et al., Neuromorphic transistors integrating photo-sensor, optical memory and visual synapses for artificial vision application. Adv. Mater. 37(27), 2419208 (2025). https://doi.org/10.1002/adma.202419208
  73. W. Fan, H. Yan, X. Wang, L. Tong, W. Yan et al., Polarization-sensitive photosynapse based on PdSe2/WS2 heterostructure for visible-infrared broadband artificial vision system. Adv. Funct. Mater. 35(43), 2416703 (2025). https://doi.org/10.1002/adfm.202416703
  74. K. Liao, K. Ding, S. Li, X. Zhang, Y. Bi et al., Enhanced near-infrared photodetection in a mixed-dimensional 0D/2D heterostructure via two-photon absorption. Laser Photonics Rev. 19(9), 2401352 (2025). https://doi.org/10.1002/lpor.202401352
  75. S. Shim, S. Kim, D. Lee, H. Kim, M.J. Kwon et al., Infrared-triggered retinomorphic artificial synapse electronic device containing multi-dimensional van der Waals heterojunctions. Small 21(24), 2410892 (2025). https://doi.org/10.1002/smll.202410892
  76. F. Ferrarese Lupi, G. Milano, A. Angelini, M. Rosero-Realpe, I. Murataj et al., Enhanced photoluminescence in a neuromorphic 2D memitter based on WS2 via plasmonic nanop self-assembly. ACS Appl. Mater. Interfaces 17(24), 35695–35704 (2025). https://doi.org/10.1021/acsami.5c03059
  77. L. Dong, B. Xue, G. Wei, S. Yuan, M. Chen et al., Highly promising 2D/1D BP-C/CNT bionic opto-olfactory co-sensory artificial synapses for multisensory integration. Adv. Sci. 11(29), 2403665 (2024). https://doi.org/10.1002/advs.202403665
  78. X. Li, K. Liu, D. Wu, P. Lin, Z. Shi et al., Van der Waals hybrid integration of 2D semimetals for broadband photodetection. Adv. Mater. 37(48), 2415717 (2025). https://doi.org/10.1002/adma.202415717
  79. H.-F. Li, J. Liu, S. Geng, T. Sun, Z. Lv et al., A 2D-3D perovskite memristor-based light-induced sensitized neuron for visual information processing. Adv. Mater. 37(42), e08342 (2025). https://doi.org/10.1002/adma.202508342
  80. J. Kang, L. Zhang, S.-H. Wei, A unified understanding of the thickness-dependent bandgap transition in hexagonal two-dimensional semiconductors. J. Phys. Chem. Lett. 7(4), 597–602 (2016). https://doi.org/10.1021/acs.jpclett.5b02687
  81. Y. Jin, K. Yu, A review of optics-based methods for thickness and surface characterization of two-dimensional materials. J. Phys. D Appl. Phys. 54(39), 393001 (2021). https://doi.org/10.1088/1361-6463/ac0f1f
  82. Y. Mao, L. Wang, C. Chen, Z. Yang, J. Wang, Thickness determination of ultrathin 2D materials empowered by machine learning algorithms. Laser Photonics Rev. 17(4), 2200357 (2023). https://doi.org/10.1002/lpor.202200357
  83. X. Sun, C. Zhu, X. Zhu, J. Yi, Y. Liu et al., Recent advances in two-dimensional heterostructures: from band alignment engineering to advanced optoelectronic applications. Adv. Electron. Mater. 7(7), 2001174 (2021). https://doi.org/10.1002/aelm.202001174
  84. H. Xu, Y. Xue, Z. Liu, Q. Tang, T. Wang et al., Van der Waals heterostructures for photoelectric, memory, and neural network applications. Small Sci. 4(4), 2470012 (2024). https://doi.org/10.1002/smsc.202470012
  85. X.-F. Luo, X.-B. Guo, D. Zhang, Q.-J. Sun, W.-H. Li et al., 2D Van der Waals heterostructure memristors: from band structure regulation to neuromorphic computing applications. Mater. Horiz. 12(18), 7277–7304 (2025). https://doi.org/10.1039/d5mh00306g
  86. X. He, X. Zhu, Z. Hong, B. Wang, W. Hong et al., Van der Waals heterojunction based self-powered biomimetic dual-mode sensor for precise object identification. Adv. Mater. 36(49), 2411121 (2024). https://doi.org/10.1002/adma.202411121
  87. Y. Zhang, Y. Tang, K. Liu, Y. Gu, L. Wang et al., Optoelectronic synapse based on Te/SnS2 heterostructure with integrated sensing-memory-computing for neuromorphic visual system. Adv. Opt. Mater. 13(26), e01371 (2025). https://doi.org/10.1002/adom.202501371
  88. W. Lv, Y. Zeng, X. Wang, W. Lv, X. Wu et al., Artificial synapse based on black phosphorus/SnS2 heterostructure transistor for neuromorphic computing with high accuracy. ACS Omega 10(42), 49766–49775 (2025). https://doi.org/10.1021/acsomega.5c04929
  89. J. Hu, M. Li, Z. Liu, Y. Ding, Y. Sun et al., Tailoring the functionalities of MoS2 field-effect transistors by an area-selective surface charge transfer doping strategy. Nano Res. 18(5), 94907360 (2025). https://doi.org/10.26599/nr.2025.94907360
  90. Z. Zhang, S. Huo, Q. Tian, F. Meng, Z. Yang et al., Near-perfect standard ternary inverter based on MoTe2 homojunction anti-ambipolar transistor. Adv. Funct. Mater. 35(29), 2424728 (2025). https://doi.org/10.1002/adfm.202424728
  91. Q. Cui, H. Shou, C. Wu, B. Tang, W. Zhu et al., Growth of monolayer WS2 lateral homojunctions via in situ domain engineering. J. Am. Chem. Soc. 147(25), 21778–21788 (2025). https://doi.org/10.1021/jacs.5c04546
  92. Y. Beckmann, A. Grundmann, L. Daniel, M. Abdelbaky, C. McAleese et al., Role of surface adsorbates on the photoresponse of (MO)CVD-grown graphene–MoS2 heterostructure photodetectors. ACS Appl. Mater. Interfaces 14(30), 35184–35193 (2022). https://doi.org/10.1021/acsami.2c06047
  93. J. Oswald, D. Beretta, M. Stiefel, R. Furrer, D. Vuillaume et al., The effect of C60 and pentacene adsorbates on the electrical properties of CVD graphene on SiO2. Nanomaterials 13(6), 1134 (2023). https://doi.org/10.3390/nano13061134
  94. S. Deng, H. Yu, T.J. Park, A.N.M.N. Islam, S. Manna et al., Selective area doping for Mott neuromorphic electronics. Sci. Adv. 9(11), eade4838 (2023). https://doi.org/10.1126/sciadv.ade4838
  95. F. Wang, K. Pei, Y. Li, H. Li, T. Zhai, 2D homojunctions for electronics and optoelectronics. Adv. Mater. 33(15), 2005303 (2021). https://doi.org/10.1002/adma.202005303
  96. S. Yang, G. Lee, J. Kim, S. Yang, C.-H. Lee, An in-plane WSe2 p–n homojunction two-dimensional diode by laser-induced doping. J. Mater. Chem. C 8(25), 8393–8398 (2020). https://doi.org/10.1039/d0tc01790f
  97. S. Aftab, H.H. Hegazy, M.Z. Iqbal, M.W. Iqbal, G. Nazir et al., Recent advances in dynamic homojunction PIN diodes based on 2D materials. Adv. Mater. Interfaces 10(6), 2201937 (2023). https://doi.org/10.1002/admi.202201937
  98. H. Park, J. Kim, Programmable synapse-like MoS2 field-effect transistors phase-engineered by dynamic lithium ion modulation. Adv. Electron. Mater. 6(5), 1901410 (2020). https://doi.org/10.1002/aelm.201901410
  99. B. Zhao, Z. Xin, Y.-C. Wang, C. Wu, W. Wang et al., Bioinspired gas-receptor synergistic interaction for high-performance two-dimensional neuromorphic devices. Matter 8(4), 102044 (2025). https://doi.org/10.1016/j.matt.2025.102044
  100. L. Liu, P. Gao, M. Zhang, J. Dou, C. Liu et al., Two-dimensional MoS2-based anisotropic synaptic transistor for neuromorphic computing by localized electron beam irradiation. Adv. Sci. 11(45), 2408210 (2024). https://doi.org/10.1002/advs.202408210
  101. K. Sun, J. Chen, X. Yan, The future of memristors: materials engineering and neural networks. Adv. Funct. Mater. 31(8), 2006773 (2021). https://doi.org/10.1002/adfm.202006773
  102. P. Thakkar, J. Gosai, H.J. Gogoi, A. Solanki, From fundamentals to frontiers: a review of memristor mechanisms, modeling and emerging applications. J. Mater. Chem. C 12(5), 1583–1608 (2024). https://doi.org/10.1039/D3TC03692H
  103. K.-S. Li, M.-K. Huang, Y.-H. Wang, Y.-C. Tseng, C.-J. Su, Wafer-scale fabrication of Al/MoS2/poly-Si memristors and insight of mechanism on the resistive switching. ACS Appl. Electron. Mater. 6(2), 777–784 (2024). https://doi.org/10.1021/acsaelm.3c01314
  104. J. Zhou, X. Zhang, Y. Zhang, S. Huang, A. Chen et al., Hardware-implemented DropConnect function for energy-efficient neuromorphic computing. Adv. Funct. Mater. 35(41), 2503452 (2025). https://doi.org/10.1002/adfm.202503452
  105. X. Wang, Q. He, H. Li, X. Zhang, H. Wang et al., Bio-inspired wide-field visual neuron implemented with ultra-low information loss population coding. Adv. Mater. 38(2), e08803 (2026). https://doi.org/10.1002/adma.202508803
  106. M. Li, Z. Liu, Y. Sun, Y. Ding, H. Chen et al., Tailoring neuroplasticity in a ferroelectric-gated multi-terminal synaptic transistor by bi-directional modulation for improved pattern edge recognition. Adv. Funct. Mater. 33(46), 2307986 (2023). https://doi.org/10.1002/adfm.202307986
  107. B.F. Yang, C. Zhang, Z.H. Zhang, D. Wang, Z.X. Wu et al., An InGaZnO synaptic transistor using titanium-oxide traps at back channel for neuromorphic computing. IEEE Trans. Electron Devices 72(6), 2943–2948 (2025). https://doi.org/10.1109/TED.2025.3558719
  108. M. Li, Y. Ding, S. Zhao, H. Wang, Z. Liu et al., Spatial information inference with programmable 2D retinomorphic devices enabling dynamic trace perception inspired by bee waggle-dance communication. Adv. Funct. Mater. 36(12), e16349 (2026). https://doi.org/10.1002/adfm.202516349
  109. S. Nam, D. Kang, S.-P. Jeon, D. Nam, J.-W. Jo et al., Contact-engineered oxide memtransistors for homeostasis-based high-linearity and precision neuromorphic computing. Small 21(7), 2409510 (2025). https://doi.org/10.1002/smll.202409510
  110. W. Dong, S. Wang, B. Zhao, C. Xu, Y. Liu et al., Planar p–n junction engineering toward reconfigurable organic synaptic transistors for high-accuracy neuromorphic recognition. Small 21(29), 2502740 (2025). https://doi.org/10.1002/smll.202502740
  111. Y. Zhou, L. Tong, Z. Chen, L. Tao, Y. Pang et al., Contact-engineered reconfigurable two-dimensional Schottky junction field-effect transistor with low leakage currents. Nat. Commun. 14, 4270 (2023). https://doi.org/10.1038/s41467-023-39705-w
  112. X. Zhang, D. Qiu, P. Hou, Plasmonic hot-electron effect enhanced WSe2 based transistor based on asymmetric Schottky contacts for self-powered photodetection and visual synapse. ACS Appl. Mater. Interfaces 17(21), 31543–31552 (2025). https://doi.org/10.1021/acsami.5c01347
  113. P. Wang, T. Zhao, S. Xiao, Q. Chen, Y. Zhang et al., Geometry-derived asymmetric Schottky contacts based on chemical vapor deposited MoS2. ACS Appl. Electron. Mater. 6(10), 7475–7483 (2024). https://doi.org/10.1021/acsaelm.4c01338
  114. Z. Cheng, J. Backman, H. Zhang, H. Abuzaid, G. Li et al., Distinct contact scaling effects in MoS2 transistors revealed with asymmetrical contact measurements. Adv. Mater. 35(21), 2210916 (2023). https://doi.org/10.1002/adma.202210916
  115. C. Liu, T. Zheng, K. Shu, S. Shu, Z. Lan et al., Polarization-sensitive self-powered Schottky photodetector with high photovoltaic performance induced by geometry-asymmetric contacts. ACS Appl. Mater. Interfaces 16(11), 13914–13926 (2024). https://doi.org/10.1021/acsami.3c16047
  116. K. Tang, C. Yan, X. Du, G. Rao, M. Zhang et al., Asymmetric contacts on narrow-bandgap black phosphorus for self-driven broadband photodetectors. Adv. Opt. Mater. 12(2), 2301350 (2024). https://doi.org/10.1002/adom.202301350
  117. J. Liu, K. Xing, L. Li, W. Zhao, A. Stacey et al., One-step transfer of symmetric and asymmetric contacts for large-scale 2D electronics and optoelectronics. ACS Nano 19(30), 27919–27929 (2025). https://doi.org/10.1021/acsnano.5c09815
  118. H. Song, Y. Li, S. Liu, X. Zhou, Y. Zhou et al., Reconfigurable graded adaptive asymmetry-Schottky-barrier phototransistor for artificial visual system with zJ-energy record. Appl. Phys. Rev. 12(2), 021418 (2025). https://doi.org/10.1063/5.0257883
  119. H. Wu, Y. Cui, J. Xu, Z. Yan, Z. Xie et al., Multifunctional half-floating-gate field-effect transistor based on MoS2–BN–graphene van der Waals heterostructures. Nano Lett. 22(6), 2328–2333 (2022). https://doi.org/10.1021/acs.nanolett.1c04737
  120. Y. Song, Z. Pan, C. Luo, Y. Wang, T. Zheng et al., Ferroelectric α-In2Se3 semi-floating gate transistors for multilevel memory and optoelectronic logic gate. ACS Appl. Mater. Interfaces 17(18), 26901–26907 (2025). https://doi.org/10.1021/acsami.5c01586
  121. Y. Pang, Y. Zhou, L. Tong, J. Xu, 2D dual gate field-effect transistor enabled versatile functions. Small 20(2), 2304173 (2024). https://doi.org/10.1002/smll.202304173
  122. Y. Zhu, Y. Wang, X. Pang, Y. Jiang, X. Liu et al., Non-volatile 2D MoS2/black phosphorus heterojunction photodiodes in the near- to mid-infrared region. Nat. Commun. 15, 6015 (2024). https://doi.org/10.1038/s41467-024-50353-6
  123. S. Zhang, S. Zhu, S. Tian, L. Zhang, C. Chen et al., Polarization-sensitive neuromorphic vision sensing enabled by pristine black arsenic-phosphorus. Light Sci. Appl. 15, 100 (2026). https://doi.org/10.1038/s41377-025-02125-0
  124. A. Rehmat, M. Asim, M. Hamza Pervez, M. Asghar Khan, S.H. Shin et al., Floating gate synaptic memory of Janus WSSe Multilayer for neuromorphic computing. Mater. Today Adv. 27, 100608 (2025). https://doi.org/10.1016/j.mtadv.2025.100608
  125. X. Wen, Z. Wang, T. Wang, J. Meng, Brain-inspired two-dimensional CuInP2S6 ferroelectric materials for neuromorphic computing. Adv. Funct. Mater. (2026). https://doi.org/10.1002/adfm.202530852
  126. Z. Lian, J. Wei, Y. Liu, Z. Liu, Y. Liu et al., Highly responsive dual-function deep-ultraviolet neuromorphic phototransistors based on silicon carbide nanop/2D MoS2 heterostructures. ACS Nano 19(28), 26041–26054 (2025). https://doi.org/10.1021/acsnano.5c06692
  127. Z. Lin, J. Chen, Z. Zheng, Q. Lai, Z. Liu et al., Multifunctional UV photodetect-memristors based on area selective fabricated Ga2S3/graphene/GaN van der Waals heterojunctions. Mater. Horiz. 12(9), 3091–3104 (2025). https://doi.org/10.1039/D4MH01711K
  128. S. Ji, J. Kim, J. Hong, J. Choi, S. Yun et al., 2D material-based memristor arrays for flexible and thermally stable neuromorphic applications. Small (2025). https://doi.org/10.1002/smll.202507845
  129. X. Zhang, M. Chi, S. Tian, J. Zhang, T. Xu et al., Asymmetric ferroelectric gated reconfigurable WSe2 p–n homojunction for in-sensor neuromorphic vision processing. Adv. Funct. Mater. 36(17), e20019 (2026). https://doi.org/10.1002/adfm.202520019
  130. C. Mahata, D. Ju, T. Das, B. Jeon, M. Ismail et al., Artificial synapses based on 2D-layered palladium diselenide heterostructure dynamic memristor for neuromorphic applications. Nano Energy 120, 109168 (2024). https://doi.org/10.1016/j.nanoen.2023.109168
  131. S. Pazos, K. Zhu, M.A. Villena, O. Alharbi, W. Zheng et al., Synaptic and neural behaviours in a standard silicon transistor. Nature 640(8057), 69–76 (2025). https://doi.org/10.1038/s41586-025-08742-4
  132. J. Park, A. Kumar, Y. Zhou, S. Oh, J.-H. Kim et al., Multi-level, forming and filament free, bulk switching trilayer RRAM for neuromorphic computing at the edge. Nat. Commun. 15, 3492 (2024). https://doi.org/10.1038/s41467-024-46682-1
  133. S.-Y. Kang, S.-M. Jin, J.-Y. Lee, D.-S. Woo, T.-H. Shim et al., Layer-dependent effects of interfacial phase-change memory for an artificial synapse. physica status solidi (RRL) – Rapid Research Letters 16(9), 2100616 (2022). https://doi.org/10.1002/pssr.202100616
  134. V.K. Sangwan, H.-S. Lee, H. Bergeron, I. Balla, M.E. Beck et al., Multi-terminal memtransistors from polycrystalline monolayer molybdenum disulfide. Nature 554(7693), 500–504 (2018). https://doi.org/10.1038/nature25747
  135. W. Huh, D. Lee, S. Jang, J.H. Kang, T.H. Yoon et al., Heterosynaptic MoS2 memtransistors emulating biological neuromodulation for energy-efficient neuromorphic electronics. Adv. Mater. 35(24), 2211525 (2023). https://doi.org/10.1002/adma.202211525
  136. X. Wang, B. Wang, Q. Zhang, Y. Sun, E. Wang et al., Grain-boundary engineering of monolayer MoS2 for energy-efficient lateral synaptic devices. Adv. Mater. 33(32), 2102435 (2021). https://doi.org/10.1002/adma.202102435
  137. M. Lanza, A. Sebastian, W.D. Lu, M.L. Gallo, M.-F. Chang et al., Memristive technologies for data storage, computation, encryption, and radio-frequency communication. Science 376(6597), eabj9979 (2022). https://doi.org/10.1126/science.abj9979
  138. J. Yang, A. Yoon, D. Lee, S. Song, I.J. Jung et al., Wafer-scale memristor array based on aligned grain boundaries of 2D molybdenum ditelluride for application to artificial synapses. Adv. Funct. Mater. 34(15), 2309455 (2024). https://doi.org/10.1002/adfm.202309455
  139. R.R. Das, T.R. Rajalekshmi, S. Pallathuvalappil, A. James, FETs for analog neural MACs. IEEE Access 12, 54019–54048 (2024). https://doi.org/10.1109/ACCESS.2024.3387094
  140. K. Zhu, S. Pazos, F. Aguirre, Y. Shen, Y. Yuan et al., Hybrid 2D–CMOS microchips for memristive applications. Nature 618(7963), 57–62 (2023). https://doi.org/10.1038/s41586-023-05973-1
  141. R. Zhao, T. Wang, T. Moon, Y. Xu, J. Zhao et al., A spiking artificial neuron based on one diffusive memristor, one transistor and one resistor. Nat. Electron. 8(12), 1211–1221 (2025). https://doi.org/10.1038/s41928-025-01488-x
  142. W. Wang, Y. Li, M. Wang, Difficulties and approaches in enabling learning-in-memory using crossbar arrays of memristors. Neuromorph. Comput. Eng. 4(3), 032002 (2024). https://doi.org/10.1088/2634-4386/ad6732
  143. T. Nazeer, S.A. Ahsan, Physics-based SPICE model of 2D-material FETs for neuromorphic circuit simulation. 2025 International Compact Modeling Conference (ICMC)., 1–4. IEEE (2025). https://doi.org/10.1109/ICMC64879.2025.11102634
  144. Y. Shi, N.T. Duong, K.-W. Ang, Emerging 2D materials hardware for in-sensor computing. Nanoscale Horiz. 10(2), 205–229 (2025). https://doi.org/10.1039/d4nh00405a
  145. G. Zhang, Q. Luo, J. Yao, S. Zhong, H. Wang et al., All-in-one neuromorphic hardware with 2D material technology: current status and future perspective. Chem. Soc. Rev. 54(18), 8196–8242 (2025). https://doi.org/10.1039/D5CS00251F
  146. J.-H. Kang, H. Shin, K.S. Kim, M.-K. Song, D. Lee et al., Monolithic 3D integration of 2D materials-based electronics towards ultimate edge computing solutions. Nat. Mater. 22(12), 1470–1477 (2023). https://doi.org/10.1038/s41563-023-01704-z
  147. J. Zhang, C. Shang, X. Dai, Y. Zhang, T. Zhu et al., Effective passivation of anisotropic 2D GeAs via graphene encapsulation for highly stable near-infrared photodetectors. ACS Appl. Mater. Interfaces 15(10), 13281–13289 (2023). https://doi.org/10.1021/acsami.2c20030
  148. S.J. Kim, H.-J. Lee, C.-H. Lee, H.W. Jang, 2D materials-based 3D integration for neuromorphic hardware. npj 2D Mater. Appl. 8, 70 (2024). https://doi.org/10.1038/s41699-024-00509-1
Read More
Author biographies are not available.
Download this PDF file
PDF