A polar-switchable and controllable negative phototransistor for information encryption

Abstract

Anomalous negative phototransistors have emerged as a distinct research area, characterized by a decrease in channel current under light illumination.

Activation of the Photosensitive Potential of 2D GaSe by Interfacial Engineering

“…These results can be ascribed to the robustness of both GaSe and MoSe 2 . Figure i presents the time-resolved photocurrent of the GaSe/MoSe 2 device at V ds = 2 V. The rise time (τ rise ) and fall time (τ fall ) are estimated as 112.4 and 426.8 μs, respectively, which is much faster than those of pure MoSe 2 device (Figure S13) and stands out among previously reported 2D photodetectors. − In principle, the τ rise is contingent upon the transport time of photocarriers, while the τ fall is mainly influenced by the recombination process of photocarriers. ,, Within the GaSe/MoSe 2 device, the variable transport and recombination times of the photocarriers result in distinct τ rise and τ fall . Similar observations have been documented in the literature concerning 2D photodetectors. , In addition, the underlying GaSe mitigates adverse effects on the SiO 2 substrate and substantially improves the carrier mobility, which accelerates the transportation of photocarriers.…”

Low-dimensional van der Waals materials for linear-polarization-sensitive photodetection: materials, polarizing strategies and applications

“…The past decade has witnessed the successful exploration of low-dimensional vdWMs for various prototypical polarization-sensitive photodetectors. However, in order to promote these devices for widespread commercialization, it is necessary to develop more applications with these devices as the pivotal functional units, such as polarization navigation [280], polarized anti-counterfeit technology [305], medical diagnosis [306,307], LiDAR [308], encrypted communications [309,310], etc.…”

Control of positive and negative photo- and thermal-responses in a single PbI2@CH3NH3PbI3 micro/nanowire-based device for real-time sensing, nonvolatile memory, and logic operation

“…In certain unique cases, the conductivity of semiconductor materials may abnormally decrease with an increase in the radiation intensity, which is referred to as a negative photoconductivity (NPC) effect. 13,14 Over the past few decades, NPC has been observed in various nanostructures including ZnO, 15–17 PbSnTe, 18 MoS 2 , 19,20 GaN, 21 GaAs, 22 WSe 2 , 23 black phosphor, 24 carbon materials, 25,26 doped Al 2 O 3 , 27,28 InAs nanowires, 29,30 SnTe quantum wells, 14,31 alloy materials, 32 Ge/Si heterojunctions, 33 and SnSe 2 junctions. 34,35 The mechanisms underlying the NPC behaviour in these materials have been proposed to involve intrinsic defects, 16,36 impurities, 37 surface plasmon resonances, 11 interface-mediated charging/discharging, 38 illumination-induced trap-states, 39 thermal scattering, 40 and desorption of adsorbed water molecules.…”