Amorphous transparent conducting oxide for van-der Waals semiconductor bifacial transparent photovoltaics

Abstract

Building integrated photovoltaic systems have necessitated the development of transparent photovoltaics (TPV). Transparent conducting oxides (TCO) play a vital role in charge carrier transport in TPVs. Their high transparency, electrical conductivity, and tunable work function make them imperative for TPV applications. Here in this work, we develop a room-temperature grown amorphous-InZnO (a-IZO) thin film for the bottom electrode for TPV. The a-IZO film has demonstrated a high average visible transmittance of 84 % over commercial F:SnO2 (FTO) substrate. A TPV with wide band gap oxide (n-Ga2O3) and a very thin layer of van der Waals material (p-SnS) was fabricated over the a-IZO thin film and commercial FTO substrate for better comparison. A significant enhancement in the current density, open-circuit voltage, and fill factor was recorded. The device with a-IZO electrode showed a bifacial power production feature with a power conversion efficiency of 3.9 % in contrast to FTO electrode-based TPV with 1.5 %. The a-IZO-based TPV also showed a good UV–vis photodetection ability with the highest responsivity of 93 mA/W and the fastest response time of 400 μs. This work suggests that enhanced photovoltaic and photodetection performance is possible using an optimum electrode design.