Polarity-Reversible Te/WSe₂ van der Waals Heterodiode for a Logic Rectifier and Polarized Short-Wave Infrared Photodetector

Abstract

As a p-type elemental material with high carrier mobility, superior ambient stability, and anisotropic crystal structure, emerging two-dimensional (2D) tellurium (Te) has been considered a successor to black phosphorus for developing infrared-related optoelectronics. Nevertheless, the lack of a scalable thickness engineering strategy remains an obstacle to unleashing its full potential. Te-based electronics with logic functions are also less explored. Herein, we propose a novel wet-chemical thinning method for 2D Te, with the merits of scalability and site-specific thickness patterning capability. A polarity-switchable van der Waals (vdW) heterodiode with a high rectification ratio of 2.4 × 103 is realized on the basis of Te/WSe2. The electronic application of this unique characteristic is demonstrated by fabricating a logic half-wave rectifier, in which the rectifying states are switchable via electrostatic gating control. Besides, the narrow band gap of Te endows the device with a broad spectral response from visible to short-wave infrared. The room-temperature responsivity reaches 5.2 A W–1 at the telecom wavelength of 1.55 μm, with an external quantum efficiency of 420% and detectivity of 6.8 × 109 Jones. In particular, owing to the intrinsic in-plane anisotropy of Te, the device exhibits a favorable photocurrent anisotropic ratio of ∼3. Our study demonstrates the enormous potential of Te for novel electronics, promoting the development of elemental 2D materials.

Vertical 1T’‐WTe2/WS2 Schottky‐Barrier Phototransistor with Polarity‐Switching Behavior

“…When a sinusoidal signal is input, the output can get the positive or negative portions, and the polarity of the half‐wave rectifier can be switched because of the gate‐modulation polarity switching in our designed WTe 2 /WS 2 diode in Figure a. [ 15 ] Figure 3b shows the schematic diagram of the polarity switchable logic half‐wave rectifier. Figure 3c shows the output V out curve of a rectifier with an input sinusoidal signal at a peak‐to‐peak voltage (the difference between the maximum positive input voltage and the maximum negative input voltage) of 4 V at the frequency of 16 Hz.…”

“…[ 12 ] Fortunately, 2D van der Waals (vdW) heterostructure obtained by artificial stacking or epitaxial growth is an efficient strategy for improving electrical and optoelectronic performance, without considering the lattice matching constraint. [ 13 ] Most importantly, various reconfigurable phenomena based on 2D vdW heterostructures can be discovered such as anti‐ambipolar behavior, [ 14 ] dynamic polarity conduction, [ 15 ] gate‐modulated rectifying behavior, [ 16 ] nonvolatile storage and memory, [ 17 ] bidirectional photoresponse, [ 18 ] etc. As a 2D reconfigurable phototransistor (RPT), the sign of the photocurrent can be modulated by bias, gate voltage (V g ), and wavelength.…”

TexSe1–x Photodiode Shortwave Infrared Detection and Imaging

“…Recently, researchers started to focus on the construction of the heterojunction of Te. Attempts have been made to form Te van der Waals heterojunctions utilizing 2D materials (such as MoS 2 , MoSe 2 , and graphene), Si and Ge etc., [26,[54][55][56][57][58] whereas suffering a slow photoresponse. Overall, the Te photodetectors mainly relied on single crystals or nanosheets and adopted the photoconductive (PC) or field-effect transistor (FET) structures, which are not conducive to CMOS integration.…”

Self‐Powered Te/Wse2 Van Der Waals Heterojunction Photodetectors With High Light On/Off Ratio And Fast Response

“…Li et al demonstrated a broadband and sensitive photodetector based on Te/WSe 2 vdWH, covering a range of 650-1550 nm. [31] Meanwhile, Cao et al reported a photodetection based on Te/In 2 S 3 heterojunction, achieving a responsivity of 303 mA/W. [32] Despite these advances, there are still challenges to overcome in realizing high-sensitivity self-powered light detection without relying on an external power supply.…”

“…demonstrated a broadband and sensitive photodetector based on Te/WSe 2 vdWH, covering a range of 650–1550 nm. [ 31 ] Meanwhile, Cao et al. reported a photodetection based on Te/In 2 S 3 heterojunction, achieving a responsivity of 303 mA/W.…”