Photoinduced Doping To Enable Tunable and High-Performance Anti-Ambipolar MoTe₂/MoS₂ Heterotransistors

Abstract

van der Waals (vdW) p–n heterojunctions formed by two-dimensional nanomaterials exhibit many physical properties and deliver functionalities to enable future electronic and optoelectronic devices. In this report, we demonstrate a tunable and high-performance anti-ambipolar transistor based on MoTe2/MoS2 heterojunction through in situ photoinduced doping. The device demonstrates a high on/off ratio of 105 with a large on-state current of several micro-amps. The peak position of the drain–source current in the transfer curve can be adjusted through the doping level across a large dynamic range. In addition, we have fabricated a tunable multivalue inverter based on the heterojunction that demonstrates precise control over its output logic states and window of midlogic through source–drain bias adjustment. The heterojunction also exhibits excellent photodetection and photovoltaic performances. Dynamic and precise modulation of the anti-ambipolar transport properties may inspire functional devices and applications of two-dimensional nanomaterials and their heterostructures of various kinds.

Spiking neurons from tunable Gaussian heterojunction transistors

“…In particular, the incorporation of atomically thin semiconducting materials into gate-tunable p-n heterojunctions results in an antiambipolar response with Gaussian transfer curves [28][29][30][31][32][33][34][35][36][37][38] . While this behavior has been used for analog signal processing 37,39 , logic devices 30,35,38 , and photodetectors 28,32,34 , the single-gated geometries used previously do not provide sufficient control over the Gaussian current-voltage characteristic to enable efficient neuromorphic functionality. Here, we report the scalable fabrication of dual-gated Gaussian heterojunction transistors (GHeTs) based on mixed-dimensional van der Waals heterojunctions 40 consisting of monolayer molybdenum disulfide (MoS 2 ) grown via chemical vapor deposition (CVD) and solution-processed semiconducting single-walled carbon nanotubes (CNTs).…”

Optically Controlled Ternary Logic Circuits Based on Organic Antiambipolar Transistors

“…As a result, the MVL operations were possible only under light irradiation in these systems. Wu et al have reported a nonvolatile memory effect on the MVL in a MoS 2 / MoTe 2 system, [27] where the UV light and writing voltage were used simultaneously to store the electrical charges at the interface. Common to these previous studies, the fact is that the light irradiation impacts mainly on the electrical charges at the interfaces.…”

“…We have utilized another merit of organic semiconductors, namely their light absorption capability over the visible to ultra‐violet (UV) wavelength range. Recently, the effect of light irradiation on AATs has allowed new optoelectronic devices to evolve, [ 6,24–28 ] , e.g., the use of the photovoltaic effect to reduce driving voltage, [ 24,25 ] the light‐triggered ternary inverter, [ 6,28 ] and light‐induced double “on” states. [ 26 ] Although these studies have led to novel optical functionalities, systematic and controlled studies are required for an in‐depth understanding of the operation mechanism.…”

Inkjet‐Printed Ternary Inverter Circuits with Tunable Middle Logic Voltages

“…These devices exhibited anti-ambipolar behavior, with inverted V-shaped transfer curves as opposed to typical V-shaped transfer curves of ambipolar field-effect transistors (FETs), and were from vdW heterojunctions composed of MoS 2 and semiconducting single-walled carbon nanotubes (SWCNTs) in 2013. [8] The reported heterojunction materials for NDR or NTC devices include 2D semiconductors that possess dangling bond-free high-quality interfaces, [9][10][11][12][13][14][15][16][17][18] organic semiconductors, [19][20][21][22][23] and hybrid material combinations. [8,[24][25][26][27][28][29] More recently, a number of ternary inverters that possess three logic states have been reported by using heterojunctions of 2D semiconductors and organic semiconductors as a promising application in digital logic circuits.…”

“…[8,[24][25][26][27][28][29] More recently, a number of ternary inverters that possess three logic states have been reported by using heterojunctions of 2D semiconductors and organic semiconductors as a promising application in digital logic circuits. [10,[12][13][14]17,18,22,23] However, reliable and scalable low-cost device fabrication methods should be developed in order to utilize integrated MVL circuits in IoT applications such as wearable electronic devices. In this regard, both 2D and organic heterojunction-based devices are not wellsuited at the current stage, because most 2D heterojunctions were formed by stacking individual mechanically exfoliated 2D flakes, while the reported organic heterojunctions were formed only by capital-intensive vacuum processes.In this work, inkjet-printed ternary inverters are presented for the first time by employing n-type indium oxide (InO) and p-type SWCNTs to form p-n heterojunctions.…”