Boosting the performance of self-powered SnO2-based UV photodetectors via Bi doping modulation for UV imaging and optical communication
Yuewu Huang, Yueying Ma, Ruiyuan Liu, Ju Huang, Zewu Xu, Guanghong Ao, Yanbin Yang, Changmiao Xie, Zhendong Fu, Erjun Guo, Dongbo Wang, Qian Xu, Liancheng Zhao
Abstract
Ultraviolet photodetectors (UVPDs) are critical components in optical sensing and communication. The creation of self-powered UVPDs that are autonomous, highly efficient, and compact is key to advancing next-generation, energy-saving, and highly integrated photonic systems. However, their optical imaging and encrypted data-transmission abilities are limited by the inadequate separation and transport of photogenerated charge carriers in semiconductor photoanode materials. Herein, we report self-powered photoelectrochemical UVPDs (SPUs), with improved charge-utilization efficiency featuring flower-like Bi-doped SnO 2 nanostructures as their photoanode. The three-dimensional flower-like nanostructures are beneficial for light absorption. Bi doping provides donor states and oxygen vacancies in SnO 2 , and these promote the separation of photogenerated carriers and suppress interface-charge recombination through band bending at the SnO 2 /electrolyte interface. The developed device achieves a high on/off ratio of 25 812, a remarkable responsivity of 0.014 A W −1 , and an impressive detectivity of 1.637×10 11 Jones, with excellent cycling and environmental stability. More importantly, our device exhibited a rapid response time of 3 ms, to our best knowledge, which is the fastest value reported for SnO 2 -based SPUs to date. Benefiting from these advantages, the device was found to exhibit high-resolution imaging capability under 0 V bias and was successfully used as a self-powered light receiver for encrypted optical communication, highlighting its possible role as an integral detection units in multifunctional optoelectronic systems.