Ultrathin Fully Vacuum-Processed Perovskite Solar Cells with Absorbers Down to 10 nm

Halide perovskites offer exceptional structural and compositional tunability, enabling next-generation photovoltaic technologies that demand high semitransparency and aesthetic integration. Here, we exploit the precise process control of thermal evaporation to grow high-quality ultrathin perovskite absorbers down to 10 nm. Fully evaporated p.i.n. perovskite solar cells (PSCs) with MAPbI3 absorbers as thin as 10, 30, and 60 nm deliver record power conversion efficiencies (PCEs) of ∼7%, ∼11%, and ∼12%, respectively. Open-circuit voltage (Voc) and fill factor (FF) remain largely comparable to PSCs with bulk absorbers (300–900 nm), indicating high optoelectronic quality and low trap density in coevaporated films. Moreover, semitransparent PSCs exhibited an average visible transparency (AVT) up to 65%, while maintaining high PCE. Indeed, ST-PSCs with a 60 nm absorber achieved a light-utilization efficiency (LUE) of 3.13% (41.24% AVT, 7.6% PCE), while a 30 nm absorber possess the highest potential LUE of 5.15%. These results mark an important step toward scalable, design-flexible, ultrathin photovoltaic systems suited for building integration and aesthetic applications.