Van der Waals heterojunctions with negative differential transconductance for broadband photodetection, multi-valued logic, and artificial neuron

Abstract

Negative differential transconductance (NDT) presents a promising platform for advancing next-generation computing technologies by reducing power consumption without increasing circuit complexity. The realization of multi-valued logic computing depends on developing innovative device concepts and circuits beyond conventional complementary metal oxide semiconductor (CMOS) technology. In this study, we demonstrate NDT behavior in an InSe/BP heterojunction at room temperature, achieving a tunable NDT with a remarkable peak-to-valley current ratio of 43.5 at V_ds = 1.4 V. The device also exhibits distinct photovoltaic behavior and a broad spectral response spanning from 520 to 1550 nm. It delivers excellent photodetection performance, with a high photoresponsivity of 561.68 A W^-1, detectivity of 3.95 × 10¹² cmHz^1/2 W^-1, an ultrahigh external quantum efficiency (EQE) of 1341.87%, and a fast response speed of 27 μs under 532 nm illumination. Even in the near-infrared regime of 1550 nm, the device maintains a responsivity of 2.21 A W^-1, detectivity of 1.23 × 10¹⁰ cmHz^1/2 W^-1, and a rise time of 477 μs. Furthermore, we successfully implemented a ternary inverter, a key component for multi-valued logic computing technology, and an artificial neuron capable of emulating neural signal transmission. This study not only highlights the exceptional electronic and optoelectronic performance of the device but also provides deeper insights into band modulation, paving the way for future advancements in low-power, high-speed logic, and neuromorphic applications.

Keywords

artificial neuron / broadband photodetection / InSe/BP heterojunction / multivalued logic / negative differential transconductance

References

[1] Keum DH, Cho S, Kim JH, et al. Bandgap opening in few-layered monoclinic MoTe₂. Nat Phys. 2015;11(6):482-486.

[2] Liu Y, Weiss NO, Duan X, Cheng H-C, Huang Y, Duan X. Van der Waals heterostructures and devices. Nat Rev Mater. 2016;1(9):16042.

[3] Zubair M, Zhu C, Sun X, et al. Record high photoresponse observed in CdS-black phosphorous van der Waals heterojunction photodiode. Sci China Mater. 2020;63(8):1570-1578.

[4] Sun X, Zhu C, Liu H, et al. Contact and injection engineering for low SS reconfigurable FETs and high gain complementary inverters. Sci Bull. 2020;65(23):2007-2013.

[5] Wu D, Mo Z, Li X, et al. Integrated mid-infrared sensing and ultrashort lasers based on wafer-level Td-WTe₂ Weyl semimetal. Appl Phys Rev. 2024;11(4):041401.

[6] Lee C-H, Lee G-H, van der Zande AM, et al. Atomically thin p–n junctions with van der Waals heterointerfaces. Nat Nanotechnol. 2014;9(9):676-681.

[7] Wu F, Li Q, Wang P, et al. High efficiency and fast van der Waals hetero-photodiodes with a unilateral depletion region. Nat Commun. 2019;10(1):4663.

[8] Xiong X, Huang M, Hu B, et al. A transverse tunnelling field-effect transistor made from a van der Waals heterostructure. Nat Electron. 2020;3(2):106-112.

[9] Bie Y-Q, Grosso G, Heuck M, et al. A MoTe₂-based light-emitting diode and photodetector for silicon photonic integrated circuits. Nat Nanotechnol. 2017;12(12):1124-1129.

[10] Wu D, Guo C, Zeng L, et al. Phase-controlled van der Waals growth of wafer-scale 2D MoTe₂ layers for integrated high-sensitivity broadband infrared photodetection. Light Sci Appl. 2023;12(1):5.

[11] Yan X, Liu C, Li C, et al. Tunable SnSe₂/WSe₂ heterostructure tunneling field effect transistor. Small. 2017;13(34):1701478.

[12] Zubair M, Wang H, Zhao Q, et al. Gate-tunable van der Waals photodiodes with an ultrahigh peak-to-valley current ratio. Small. 2023;19(29):2300010.

[13] Li D, Chen M, Sun Z, et al. Two-dimensional non-volatile programmable p–n junctions. Nat Nanotechnol. 2017;12(9):901-906.

[14] Zubair M, Dong Y, Cai B, et al. Floating gate photo-memory devices based on van der Waals heterostructures for neuromorphic image recognition. Appl Phys Lett. 2023;123(5):051102.

[15] Feng G, Liu Y, Zhu Q, et al. Giant tunnel electroresistance through a Van der Waals junction by external ferroelectric polarization. Nat Commun. 2024;15(1):9701.

[16] Jariwala D, Sangwan VK, Wu C-C, et al. Gate-tunable carbon nanotube–MoS₂ heterojunction p–n diode. Proc Natl Acad Sci. 2013;110(45):18076-18080.

[17] Lv Q, Yan F, Mori N, et al. Interlayer band-to-band tunneling and negative differential resistance in van der Waals BP/InSe field-effect transistors. Adv Funct Mater. 2020;30(15):1910713.

[18] Shim J, Oh S, Kang D-H, et al. Phosphorene/rhenium disulfide heterojunction-based negative differential resistance device for multi-valued logic. Nat Commun. 2016;7(1):13413.

[19] Paul Inbaraj CR, Mathew RJ, Ulaganathan RK, et al. A Bi-anti-ambipolar field effect transistor. ACS Nano. 2021;15(5):8686-8693.

[20] Lee C, Lee C, Lee S, Choi J, Yoo H, Im SG. A reconfigurable binary/ternary logic conversion-in-memory based on drain-aligned floating-gate heterojunction transistors. Nat Commun. 2023;14(1):3757.

[21] Li W, Yang R, Han X, et al. Bias tunable SnS₂/ReSe₂ tunneling photodetector with high responsivity and fast response speed. Small. 2025;21(5):2408379.

[22] Yan R, Fathipour S, Han Y, et al. Esaki diodes in van der Waals heterojunctions with broken-gap energy band alignment. Nano Lett. 2015;15(9):5791-5798.

[23] Huang M, Li S, Zhang Z, Xiong X, Li X, Wu Y. Multifunctional high-performance van der Waals heterostructures. Nat Nanotechnol. 2017;12(12):1148-1154.

[24] Fan S, Vu QA, Lee S, et al. Tunable negative differential resistance in van der Waals heterostructures at room temperature by tailoring the interface. ACS Nano. 2019;13(7):8193-8201.

[25] Seo S, Cho J-I, Jung K-S, et al. A van der Waals reconfigurable multi-valued logic device and circuit based on tunable negative-differential-resistance phenomenon. Adv Mater. 2022;34(36):2202799.

[26] Lin Y-C, Ghosh RK, Addou R, et al. Atomically thin resonant tunnel diodes built from synthetic van der Waals heterostructures. Nat Commun. 2015;6(1):7311.

[27] Chen C-F, Yang S-H, Lin C-Y, et al. Reversible charge-polarity control for multioperation-mode transistors based on van der Waals heterostructures. Adv Sci. 2022;9(24):2106016.

[28] Andreev M, Kang J, Lee T, et al. Electron-beam-induced negative differential transconductance homojunction device based on van der Waals materials for functionally complete ternary computing. ACS Nano. 2024;18(52):35276-35285.

[29] Xu H, Xie R, Miao J, et al. Critical band-to-band-tunnelling based optoelectronic memory. Light Sci Appl. 2025;14(1):72.

[30] Cen Y, Tu Y, Zhu J, Hu Y, Hao Q, Zhang W. Photoinduced contact evolution and junction rearrangement in two-dimensional van der Waals heterostructure. Adv Funct Mater. 2023;33(48):2306668.

[31] Gao A, Lai J, Wang Y, et al. Observation of ballistic avalanche phenomena in nanoscale vertical InSe/BP heterostructures. Nat Nanotechnol. 2019;14(3):217-222.

[32] He T, Wang Z, Cao R, et al. Extrinsic photoconduction induced short-wavelength infrared photodetectors based on Ge-based chalcogenides. Small. 2021;17(4):2006765.

[33] Qu J, Liu C, Zubair M, et al. A universal growth method for high-quality phase-engineered germanium chalcogenide nanosheets. Nanoscale. 2023;15(9):4438-4447.

[34] Zeng L, Wu D, Jie J, et al. Van der Waals epitaxial growth of mosaic-like 2D platinum ditelluride layers for room-temperature mid-infrared photodetection up to 10.6 μm. Adv Mater. 2020;32(52):2004412.

[35] Zeng L, Han W, Ren X, et al. Uncooled mid-infrared sensing enabled by chip-integrated low-temperature-grown 2D PdTe₂ dirac semimetal. Nano Lett. 2023;23(17):8241-8248.

[36] Wang J, Han J, Chen X, Wang X. Design strategies for two-dimensional material photodetectors to enhance device performance. InfoMat. 2019;1(1):33-53.

[37] Xue H, Wang Y, Dai Y, et al. A MoSe₂/WSe₂ heterojunction-based photodetector at telecommunication wavelengths. Adv Funct Mater. 2018;28(47):1804388.

[38] Kang X, Lan C, Li F, et al. Van der Waals PdSe₂/WS₂ heterostructures for robust high-performance broadband photodetection from visible to infrared optical communication band. Adv Opt Mater. 2021;9(7):2001991.

[39] Chen X, Lu X, Deng B, et al. Widely tunable black phosphorus mid-infrared photodetector. Nat Commun. 2017;8(1):1672.

[40] Xie Y, Wu E, Zhang J, Hu X, Zhang D, Liu J. Gate-tunable photodetection/voltaic device based on BP/MoTe₂ heterostructure. ACS Appl Mater Interfaces. 2019;11(15):14215-14221.

[41] Dai M, Chen H, Wang F, et al. Ultrafast and sensitive self-powered photodetector featuring self-limited depletion region and fully depleted channel with van der Waals contacts. ACS Nano. 2020;14(7):9098-9106.

[42] Zhao Y, Cho J, Choi M, et al. Light-tunable polarity and erasable physisorption-induced memory effect in vertically stacked InSe/SnS₂ self-powered photodetector. ACS Nano. 2022;16(10):17347-17355.

[43] Cao S, Xing Y, Han J, et al. Ultrahigh-photoresponsive UV photodetector based on a BP/ReS₂ heterostructure p–n diode. Nanoscale. 2018;10(35):16805-16811.

[44] Ahmad W, Liu J, Jiang J, et al. Strong interlayer transition in few-layer InSe/PdSe₂ van der Waals heterostructure for near-infrared photodetection. Adv Funct Mater. 2021;31(43):2104143.

[45] Li W, Yang R, Han X, et al. Bias tunable SnS₂/ReSe₂ tunneling photodetector with high responsivity and fast response speed. Small. 2025;21(5):2408379.

[46] Ma H, Xing Y, Han J, et al. Ultrasensitive and broad-spectrum photodetectors based on InSe/ReS₂ heterostructure. Adv Opt Mater. 2022;10(5):2101772.

[47] Zhao X, Zhao D, Hu T, et al. Carrier recirculation induced ultrasensitive photodetectors of InSe/CdTe heterostructure featuring an interfacial holes layer. Small. 2025;21(6):2408826.

[48] Balaji Y, Smets Q, Śzabo Á, et al. MoS₂/MoTe₂ heterostructure tunnel FETs using gated Schottky contacts. Adv Funct Mater. 2020;30(4):1905970.

[49] Srivastava PK, Hassan Y, Gebredingle Y, et al. Multifunctional van der Waals broken-gap heterojunction. Small. 2019;15(11):1804885.

[50] Lee J, Duong NT, Bang S, et al. Modulation of junction modes in SnSe₂/MoTe₂ broken-gap van der Waals heterostructure for multifunctional devices. Nano Lett. 2020;20(4):2370-2377.

[51] Fave A, Lelièvre J-F, Gallet T, Su Q, Lemiti M. Fabrication of Si tunnel diodes for c-Si based tandem solar cells using proximity rapid thermal diffusion. Energy Procedia. 2017;124:577-583.

[52] Schulte-Braucks C, Stange D, Driesch N, et al. Negative differential resistance in direct bandgap GeSn p–i–n structures. Appl Phys Lett. 2015;107(4):042101.

[53] Wu F, Tian H, Yan Z, et al. Gate-tunable negative differential resistance behaviors in a hBN-encapsulated BP-MoS₂ heterojunction. ACS Appl Mater Interfaces. 2021;13(22):26161-26169.

[54] Zhang Z, Zhang B, Wang Y, et al. Toward high-peak-to-valley-ratio graphene resonant tunneling diodes. Nano Lett. 2023;23(17):8132-8139.

[55] Cheng R, Yin L, Hu R, et al. Modulation of negative differential resistance in black phosphorus transistors. Adv Mater. 2021;33(25):2008329.

[56] Duong NT, Bang S, Lee SM, et al. Parameter control for enhanced peak-to-valley current ratio in a MoS₂/MoTe₂ van der Waals heterostructure. Nanoscale. 2018;10(26):12322-12329.

[57] Xiong X, Kang J, Hu Q, et al. Reconfigurable logic-in-memory and multilingual artificial synapses based on 2D heterostructures. Adv Funct Mater. 2020;30(11):1909645.

[58] Jung K-S, Heo K, Kim M-J, et al. Double negative differential resistance device based on hafnium disulfide/pentacene hybrid structure. Adv Sci. 2020;7(19):2000991.

[59] Afzal AM, Iqbal MZ, Iqbal MW, et al. High performance and gate-controlled GeSe/HfS₂ negative differential resistance device. RSC Adv. 2022;12(3):1278-1286.

[60] Liu X, Deng C, Wei H, et al. High-sensitive uncooled mid-wave infrared photodetector based on PtSe₂/MoTe₂ heterojunction with fast speed. Adv Funct Mater. 2025;2423102.

[61] Ye L, Li H, Chen Z, Xu J. Near-infrared photodetector based on MoS₂/black phosphorus heterojunction. ACS Photonics. 2016;3(4):692-699.

[62] Wu F, Xia H, Sun H, et al. AsP/InSe Van der Waals tunneling heterojunctions with ultrahigh reverse rectification ratio and high photosensitivity. Adv Funct Mater. 2019;29(12):1900314.

[63] Harikesh PC, Yang C-Y, Wu H-Y, et al. Ion-tunable antiambipolarity in mixed ion–electron conducting polymers enables biorealistic organic electrochemical neurons. Nat Mater. 2023;22(2):242-248.

[64] Danneville F, Loyez C, Carpentier K, Sourikopoulos I, Mercier E, Cappy A. A sub-35 pW Axon-Hillock artificial neuron circuit. Solid State Electron. 2019;153:88-92.

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