Two-dimensional(2D)ternary wide-bandgap semiconducting materials have great potential in power device,flexible electronic device,short-wavelength light emitting diodes(LEDs)and photodetectors due to the controllable bandgap,strong light-material interaction,and controlled freedom degree of stoichiometry variation.However,it is still a great challenge to precisely control the growth of high-quality 2D ternary wide-bandgap semiconducting materials due to the variety of components,which hinders their development for practical applications.In this work,high-quality 2D ternary bismuth oxybromide single-crystal nanosheets with a high yield were prepared by space-confined chemical vapor deposition(CVD)method.The devices based on 2D ultrathin BiOBr single-crystal nanoflakes show a high UV detecting performance including low dark current(Idark)of 1.46pA and high re s ponsivity(R),external quantum efficiency(EQE)and detectivity(D*)of 14.96 A W-1,5460%,and 5.74 × 10^10 Jones,respectively,as well as fast response process(τrise=80 ms,τdecay=40 ms).The excellent UV performance can be ascribed to the photogating effect by trapped states,which endow it with great potential for high-performance UV detectors.
Nanodevices using the photovoltaic effect of a single nanowire have attracted growing interest. In this paper, we consider potential applications of the photovoltaic effect to optical signal coupling and optical power transmission, and report on the realization of a heterojunction formed between WO2 and WO3 in a fine-wire having a diameter on the micrometer scale. Using a laser beam of 514.5 nm as a signal source, the WO2-WO3 heterojunction yields a maximum output power of up to 37.4 pico watt per heterojunction. Fast responses （less than a second） of both photovoltaic voltage and current are also observed. In addition, we demonstrate that it is a simple and effective way to adapt a commercial Raman spectrometer for the combined functions of fabrication, material characterization and photovottaic measurement of an optical signal coupler and optical power transmitter based on a fine-wire. Our results show an attractive perspective of developing nanowire or fine-wire elements for coupling optical signals into and for powering a nanoelectronic or nano-optoelectronic integrated circuit that works under the condition of preventing it from directly electrically connecting with the optical coupler.
