Homo‐type α‐In₂Se₃/PdSe₂ Ferroelectric van der Waals Heterojunction Photodetectors with High‐performance and Broadband

Abstract

Two‐dimensional (2D) materials have attracted extensive attention in the field of photodetection thanks to their unique physical properties. Among them, the PdSe2 nanoflake shows great potential. However, the performance of the PdSe2‐based photodetector with a hetero‐type heterojunction remains poor due to the severe tunneling‐assisted interfacial recombination of photogenerated electron‐hole pairs in the thin bilateral‐depletion heterojunctions. In this work, a novel photodetector with a α‐In2Se3/PdSe2 homo‐type heterojunction for both high‐performance and broadband detection from visible to short‐wave infrared is constructed. The high‐performance of the photoresponsivity of 4.64 × 103 A·W−1, the external quantum efficiency of 1.08 × 106%, and the specific detectivity of 1.55 × 1014 Jones at 532 nm is the result of the homo‐type unilateral‐depletion junction which can promote the effective separation of photogenerated electron‐hole pairs compared to the hetero‐type. Also, adjusting the α‐In2Se3 ferroelectric polarization state further optimizes the unilateral depletion region. In addition, the photodetector can work in a self‐powered mode. This study suggests that the PdSe2‐based homo‐type device has great application potential in the field of 2D optoelectronics.

Effect of doping and defects on the electronic properties of MoS2/WSe2 bilayer heterostructure: a first-principles study

“…10,11 Examples include vertical FETs fabricated by graphene/MoS 2 heterojunctions that exhibit a high current density of 5000 A cm −2 and an on–off ratio > 1000, 12 optically and electrically tunable planar memristors based on ReS 2 /WS 2 van der Waals heterojunctions that have unique unipolar nonvolatility, 13 and photodetectors based on α-In2Se 3 /PdSe 2 heterojunctions for high-performance and broadband detection from the visible to the short-wave infrared. 14 Theoretical calculations of bilayer TMD/TMD heterostructure have been extensively and intensively studied. 15 Most of these works focus on the effects of twist, 16,17 strain, 18,19 and applied electric field 20 on the electronic properties of heterostructures.…”

Photodetectors Based on ZrS3/MoS2 Heterostructures

“…Generally, R, D*, and EQE are strongly dependent on light power and wavelength, and concretely speaking, they all show an overall decay tendency with increasing light intensity and wavelength, consistent with the behaviors of other reported 2D materialbased heterojunctions. 47,48 The highest R, D*, and EQE reach 212 A/W, 5.0 × 10 11 Jones, and 8.5 × 10 4 %, respectively, under the conditions with λ = 310 nm, P = 10 mW/cm 2 , and V ds = 2 V. Notable, too, are the corresponding values also as high as 73 A/W, 1.7 × 10 11 Jones, and 1.4 × 10 4 % at the same conditions with λ = 638 nm, which is close to the material band-gap edge of ZrS 3 and MoS 2 . In detail, under 310 light illumination, the quantities of R, D*, and EQE increase when the light intensity is over 80 mW/cm 2 .…”