Nonvolatile and Programmable Photodoping in MoTe₂ for Photoresist‐Free Complementary Electronic Devices

Abstract

2D transition‐metal dichalcogenide (TMD)‐based electronic devices have been extensively explored toward the post‐Moore era. Huge efforts have been devoted to modulating the doping profile of TMDs to achieve 2D p–n junctions and inverters, the fundamental units in logic circuits. Here, photoinduced nonvolatile and programmable electron doping in MoTe2 based on a heterostructure of MoTe2 and hexagonal boron nitride (BN) is reported. The electron transport property in the MoTe2 device can be precisely controlled by modulating the magnitude of the photodoping gate exerted on BN. Through tuning the polarity of the photodoping gate exerted on BN under illumination, such a doping effect in MoTe2 can be programmed with excellent repeatability and is retained for over 14 d in the absence of an external perturbation. By spatially controlling the photodoping region in MoTe2, a photoresist‐free p–n junction and inverter in the MoTe2 homostructure are achieved. The MoTe2 diode exhibits a near‐unity ideality factor of ≈1.13 with a rectification ratio of ≈1.7 × 104. Moreover, the gain of the MoTe2 inverter reaches ≈98, which is among the highest values for 2D‐material‐based homoinverters. These findings promise photodoping as an effective method to achieve 2D‐TMDs‐based nonvolatile and programmable complementary electronic devices.

Van der Waals Heterostructures with Tunable Tunneling Behavior Enabled by MoO3 Surface Functionalization

“…The transfer curves ( I sd – V g ) of MoS 2 , MoTe 2 , and vdWHs under high vacuum (10 −7 mbar) are shown in Figure d. The pristine MoTe 2 device shows a typical hole‐dominated ambipolar transport behavior and the MoS 2 transistor exhibits electron transport characteristics, consistent with previous reports . The pristine transfer characteristics of vdWHs shows anti‐ambipolar transport behavior ascribed to the recombination of the free holes in MoTe 2 and the free electrons in MoS 2 , which further verifies the type II band alignment in this pristine heterostructure device .…”

Recent Advances in Ambipolar Transistors for Functional Applications

“…Lim et al exploited atomic‐layer‐deposition‐generated H‐doping to achieve electron‐dominated α‐MoTe 2 flake with electron mobility of 18 cm 2 V −1 s −1 , which finally gave rise to stable CMOS inverters with large gain value (29) and small static power dissipation on the order of nanowatts . Very recently, by combining MoTe 2 with BN and forming a heterostructure between them, Liu et al proposed a photodoping method to accurately adjust the electron conduction characteristics (concentration and mobility of electrons) of MoTe 2 FET via tuning the amplitude of the applied photodoping gate . It was found that the induced photodoping effect was repeatable and nonvolatile and could be maintained for more than 14 days without ambient stimulation.…”

“…c) The obtained voltage gain values of the MoTe 2 inverter under different input biases. It is found that the maximum gain value increases from 18, 42, to 98 when V DD augments from 1, 2 to 3 V. Reproduced with permission . Copyright 2018, Wiley‐VCH.…”

Anomalous Broadband Spectrum Photodetection in 2D Rhenium Disulfide Transistor

“…Photodetectors, converting light into electrical signal, demonstrate a wide range of applications in our daily lives, including optical telecommunications, remote sensing, video imaging, motion detection, and so forth . 2D layered materials have been rapidly established as promising building blocks for state‐of‐the‐art photodetectors, owing to their unique crystal structure and optical/electrical properties . 2D materials possess a layered structure, in which the atoms within each layer are covalently bonded, while different layers are held together by van der Waals interactions.…”