High-Efficiency Semitransparent Perovskite Solar Cells Enabled by Controlling the Crystallization of Ultrathin Films
Rabindranath Garai, Bhavna Sharma, Mohammad Adil Afroz, Shivani Choudhary, Tejasvini Sharma, Isaac Metcalf, Naveen Kumar Tailor, Parameswar Krishnan Iyer, Aditya D. Mohite, Soumitra Satapathi
Abstract
Semitransparent perovskite solar cells (ST-PSCs) have emerged as an exciting prospect due to their applications in future smart buildings. Semitransparency is typically realized through the use of wide bandgap perovskite materials with a reduced thickness. In this study, we demonstrate a methylammonium (MA)-free wide bandgap perovskite for the active layer of ST-PSCs. However, achieving defect-free highly crystalline films with lower film thickness has been challenging. We report a precursor engineering approach based on an organic ammonium salt tryptamine hydro bromide (TABr) with an anion and a cation group to passivate both halide and metal ion vacancies. TABr molecules regulate the crystallization kinetics and offer highly crystalline thinner perovskite films. The champion device exhibits a power conversion efficiency (PCE) of 14.21%, along with an average visible transparency (AVT) of ∼22%. This work provides an efficient method to enhance the performance of ST-PSCs with high AVT for application in building integrated photovoltaics (BIPVs).