Faculty of Information Technology , Macau University of Science and Technology , Taipa , Macau SAR 999078 , P. R. China.
Collaborative Innovation Center for Optoelectronic Science and Technology and Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province , Shenzhen University , Shenzhen 518060 , P. R. China.
ACS Appl Mater Interfaces. 2019 Jan 30;11(4):4278-4287. doi: 10.1021/acsami.8b19836. Epub 2019 Jan 17.
Owing to the attractive energy band properties, a black phosphorus (BP)-analogue semiconductor, germanium selenide (GeSe), shows a promising potential applied for optoelectronic devices. Herein, ultrathin GeSe nanosheets were systematically prepared via a facile liquid-phase exfoliation approach, with controllable nanoscale thickness. Different from BP, ultrathin GeSe nanosheets exhibit good stability under both liquid and ambient conditions. Besides, its ultrafast carrier dynamics was probed by transient absorption spectroscopy. We showed that the GeSe nanosheet-based photodetector exhibits excellent photoresponse behaviors ranging from ultraviolet (UV) to the visible regime, with high responsivity and low dark current. Furthermore, the detective ability of such a device can be effectively modulated by varying the applied bias potential, light intensity, and concentration of the electrolyte. Generally, our present contribution could not only supply fundamental knowledge of a GeSe nanosheet-based photoelectrochemical (PEC)-type device, but also offer guidance to extend other possible semiconductor materials in the application of the PEC-type photodetector.
由于具有吸引人的能带特性，黑磷（BP）类似的半导体硒化锗（GeSe）在光电器件应用方面显示出了有前景的潜力。本文通过一种简便的液相剥离方法，系统地制备了具有可控纳米级厚度的超薄 GeSe 纳米片。与 BP 不同，超薄 GeSe 纳米片在液体和环境条件下均表现出良好的稳定性。此外，通过瞬态吸收光谱研究了其超快载流子动力学。我们表明，基于 GeSe 纳米片的光电探测器在紫外（UV）到可见区域均表现出优异的光电响应行为，具有高响应度和低暗电流。此外，通过改变外加偏压、光强和电解质浓度可以有效地调节该器件的探测能力。总的来说，本研究不仅为基于 GeSe 纳米片的光电化学（PEC）型器件提供了基本认识，而且为扩展其他可能的半导体材料在 PEC 型光电探测器中的应用提供了指导。
