Giant‐Enhanced SnS₂ Photodetectors with Broadband Response through Oxygen Plasma Treatment

Abstract

Layered tin disulfide (SnS2) is a vital semiconductor with versatile functionality due to its high carrier mobility and excellent photoresponsivity. However, the intrinsic defects Vs (sulfur vacancies), which cause Fermi level pinning (significant metal contact resistance), hinder its electrical and optoelectrical performance. Herein, oxygen plasma treatment is employed to enhance the optoelectronic performance of SnS2 flakes, which results in artificial sub‐bandgap in SnS2. Consequently, the broadband photosensing (300–750 nm) is remarkably improved. Specifically, under 350 nm illumination, the O2‐plasma‐treated SnS2 photodetector exhibits an enhanced photoresponsivity from 385 to 860 A W−1, the external quantum efficiency and the detectivity improve by one order of magnitude as well as increase the photoswitching response improvement by two orders of magnitude for both rising (τr) and decay (τd) time. This artificial sub‐bandgap can both improve the photoresponse and broaden the response spectra, which paves a new path for the applications of optoelectronics.

Recent Advances in 2D Materials for Photodetectors

“…Especially, Yu et al. [ 53 ] found oxygen plasma treatment could effectively adjust the performance of SnS 2 ‐based photodetector. This device exhibits an obvious enhanced responsivity, photoresponse time D * , and EQE, which is ascribed to the replacement of the intrinsic vacancies by the introduced oxygen atoms.…”

Graphdiyne Visible‐Light Photodetector with Ultrafast Detectivity

“…Besides, the intrinsically high carrier mobility of GDY can reach 51.5 cm 2 V −1 s −1 (Figure S14, Supporting Information), which exceeds the value obtained in GDY films prepared through the conventional method, [ 23 ] allowing the holes/electrons to pass through the channel in a short time. [ 24 ] Compared with previously reported photodetectors composed of perovskite, transition metal sulfide/selenide, and even a heterostructure, [ 21,22,24–42 ] the short response and recovery times of GDY‐PDs are indeed impressive as Figure 4e shows. It can be intuitively seen that the visible‐light detector based on our GDY thin film has tremendous advantages in terms of quick response, which is superior to most mainstream photoelectronic materials involving inorganic semiconductors such as perovskite and transition metal sulfide/selenide.…”

A Self‐Powered Photodetector Based on MAPbI3 Single‐Crystal Film/n‐Si Heterojunction with Broadband Response Enhanced by Pyro‐Phototronic and Piezo‐Phototronic Effects

“…Organic–inorganic halide perovskite materials such as MAPbI 3 (MA = CH 3 NH 3 + ) have attracted much attention for their various optoelectronic applications, such as solar cells, [ 1–4 ] lasers, [ 5–7 ] light‐emitting diodes, [ 8–11 ] and photodetectors (PDs), [ 12–15 ] due to their large light absorption coefficient, high carrier mobility, long carrier diffusion length, low trap density and, tunable bandgap. Nowadays, sensitive PDs with broadband responses are highly desirable for multicolor light detection applications, [ 16–19 ] such as environmental monitoring and day/night‐time surveillance. Up to now, PDs based on halide perovskites based on different operational mechanisms with excellent performance have been widely exploited, and great progress has been made.…”