Authors: Jidong Li, Yuyang Long, Zhili Hu, Jiyuan Niu, Tiezhu Xu, Maolin Yu, Baowen Li, Xuemei Li, Jianxin Zhou, Yanpeng Liu, Cheng Wang, Laifa Shen, Wanlin Guo, Jun Yin
Published: 2021-08-17
DOI: 10.1038/s41467-021-25318-8
Source: Full article
AbstractExternal photo-stimuli on heterojunctions commonly induce an electric potential gradient across the interface therein, such as photovoltaic effect, giving rise to various present-day technical devices. In contrast, in-plane potential gradient along the interface has been rarely observed. Here we show that scanning a light beam can induce a persistent in-plane photoelectric voltage along, instead of across, silicon-water interfaces. It is attributed to the following movement of a charge packet in the vicinity of the silicon surface, whose formation is driven by the light-induced potential change across the capacitive interface and a high permittivity of water with large polarity. Other polar liquids and hydrogel on silicon also allow the generation of the in-plane photovoltage, which is, however, negligible for nonpolar liquids. Based on the finding, a portable silicon-hydrogel array has been constructed for detecting the shadow path of a moving Cubaris. Our study opens a window for silicon-based photoelectronics through introducing semiconductor-water interfaces.