High-Performance Broadband Photoelectrochemical Photodetectors Based on Ultrathin Bi₂O₂S Nanosheets

Abstract

Two-dimensional (2D) bismuth oxychalcogenide (Bi2O2X, X refers to S, Se, and Te) is one type of rising semiconductor with excellent electrical transport properties, high photoresponse, and good air stability. However, the research on 2D Bi2O2S is limited. In this work, ultrathin Bi2O2S nanosheets are synthesized by a facile and eco-friendly chemical synthesis method at room temperature. The thickness and lateral sizes are 2–4 nm and 20–40 nm, respectively. The 2D ultrathin Bi2O2S nanosheets have a broad absorption spectrum from ultraviolet (UV) to near-infrared (NIR). Photoelectrochemical (PEC) photodetectors based on 2D Bi2O2S nanosheets are fabricated by a simple drop-casting method. The 2D Bi2O2S-based PEC photodetectors show excellent photodetection performance with a broad photoresponse spectrum from 365 to 850 nm, a high responsivity of 13.0 mA/W, ultrafast response times of 10/45 ms, and good long-term stability at a bias voltage of 0.6 V, which are superior to most 2D material-based PEC photodetectors. Further, the 2D Bi2O2S PEC photodetector can function as a high-performance self-powered broadband photodetector. Moreover, the photoresponse performance can be effectively tuned by the concentration and the kind of electrolyte. Our results demonstrate that 2D Bi2O2S nanosheets hold great promise for application in high-performance optoelectronic devices.

MOF-Derived In2O3 Microrods for High-Performance Photoelectrochemical Ultraviolet Photodetectors

“…The In 2 O 3 MR PEC PDs exhibit a high D * value of 2.03 × 10 10 Jones for 365 nm irradiation (level I, more details in Table S5). The photoresponse performance of In 2 O 3 MR PEC PDs surpasses most recently reported aqueous-type PEC UV PDs and several solid-state PDs (more details in Figure d ,,,− and Table S6 ). The high R , high D *, and simple fabrication process make In 2 O 3 MR PEC PDs have great potential application in high-performance UV PDs.…”

“…After 100 cycles of illumination, I ph decreases from 34.92 to 32.46 μA/cm 2 for the fresh sample, maintaining 92.96% of the initial value, which demonstrates a good multicycle stability of In 2 O 3 MR PEC PDs. The multicycle stability of In 2 O 3 MR PEC PDs is better than that of most reported PEC PDs, such as graphdiyne (GDY)-based PD (11.7% decay after 1000 s) and Bi 2 O 2 S-based PD (30% decay after 5000 s) . Three months later, I ph decreases to 28.83 μA, which maintains 82.6% of the initial value (34.92 μA/cm 2 ), revealing the good long-term stability of In 2 O 3 MR PEC PDs.…”

“…The spectral photoresponse behavior is quantitatively evaluated by UV/visible ( R 365nm / R 455nm ) reject ratio. The UV/visible reject ratio of In 2 O 3 MR PEC PDs is 20.77, which not only surpasses some metal-oxide UV PDs, such as SnO 2 ( R 300nm / R 450nm = 10.74) and Bi 2 O 2 S ( R 365nm / R 455nm = 8.33), but also outstrips some two-dimensional (2D) material-based UV PDs, such as GeSe ( R 365nm / R 475nm = 3.76), V 2 O 5 ( R 365nm / R 554nm = 1.56), and PbS ( R 350nm / R 475nm = 1.72). The specific detectivity ( D *) is obtained through the following equation: D * = R × S 1/2 /(2 × q × I d ) 1/2 , where q is the charge of an electron (1.6 × 10 –19 C).…”

Self-Powered Photoelectrochemical Photodetectors Based on Electrochemically Exfoliated In2Se3 Nanosheets

“…Recently, photoelectrochemical (PEC)-type photodetectors have attracted much attention because of their low manufacturing cost, self-powered capability, and high performance. − Several 2D materials, such as Bi 2 O 2 S, GaS, and WS 2 , have been investigated in PEC photodetectors. − Most 2D material PEC photodetectors are fabricated from 2D materials synthesized by liquid-phase exfoliation, which usually show a slow response speed of up to several seconds . Compared with liquid-phase exfoliation and mechanical exfoliation, electrochemical exfoliation is a more powerful method for synthesizing 2D layered materials with a high crystalline quality, rapid fabrication, and controllable thickness .…”

Effect of hydrostatic pressure on stereochemically active lone-pair of Bi$_2$O$_2$S

“…4 In particular, dibismuth dioxychalcogenides, Bi 2 O 2 Ch (Ch = S, Se, Te), their 2D counterparts, [5][6][7] and heterostructures 8 gained tremendous research interest due to their potential applications in thermoelectrics, 4,9,10 ferroelectrics, 11 and optoelectronics. 4,6,[12][13][14] The ternary Bi 2 O 2 Ch systems are synthesized by a solid state reaction of well-known binary thermoelectric bismuth chalcogenides Bi 2 Ch 3 (Ch = S, Se, Te) with Bi 2 O 3 . Bi 2 O 2 S crystallizes in the primitive orthorhombic structure (SG: P nmn, Z=2 formula units (f.u.)…”