Biopolymer-based buried interface modification for efficient semitransparent perovskite solar cells with improved carrier dynamics

Abstract

Semitransparent perovskite solar cells (ST-PSCs) have potential application in buildings and vehicle integrated photovoltaics (IPV) to maximize the use of solar energy. However, to satisfy the criteria for applications in IPV, it is still challenging for ST-PSCs to simultaneously achieve high photoelectric conversion efficiency (PCE) and decent average visible transmittance (AVT). Herein, we firstly choose the commonly used Cs_0.1FA_0.9PbI₃ perovskite to study the relationship between perovskite film thickness and crystallization quality for achieving an optimal perovskite film with high transmittance and excellent crystallization. Then, the natural biopolymer sodium hyaluronate (HA) was applied as an interface layer between the hole transport layer and the perovskite layer to further passivate interface defects, regulate carrier dynamics and improve device photovoltaic performance. Results show that HA effectively passivates the defects in the nickel oxide (NiO_x) and perovskite layers, enhances the crystalline quality of the perovskite film, inhibits non-radiative recombination at the interface, and increases the carrier extraction rate. Therefore, the ST-PSC device with HA modification achieves a maximum PCE of 16.02%, with an AVT of 33% and a light utilization rate of 5.28%. In addition, the device retains about 92% of its initial PCE after aging for 1100 h in air with 30–40% relative humidity. This work provides a simple and efficient method to optimize crystalline quality and improve interface carrier dynamics for achieving ST-PSCs with high PCE and AVT.