Random Micro‐Pyramids for Transparent c ‐Si Solar Cells: Enabling 16.1% Efficiency with Wavelength‐Independent 20% Transmittance

Abstract Transparent photovoltaics (TPVs) hold immense promise for applications where aesthetic appeal and functional performance align, such as building‐integrated photovoltaics. Among TPV technologies, crystalline silicon ( c ‐Si) TPVs have emerged as a leading candidate owing to their glass‐like transparency, high efficiency, and long‐term stability. However, their overall performance is limited by light loss in transparent regions, which necessitates strategies to maximize light absorption in the active c ‐Si areas. In this study, a straightforward yet effective approach is presented to enhance light absorption in c ‐Si TPVs by forming random micro‐pyramid structures on the c ‐Si surface via a simple wet‐chemical process. These surface structures significantly improve light absorption without compromising visual transparency. This improvement translates into record short‐circuit current density ( J _SC ) of 32.7 mA cm ⁻² for a 1 cm ² device. When scaled up to a 25 cm ² device, the J _SC further increases to 33.3 mA cm ⁻² , achieving an efficiency of 16.1%, which is the highest reported value to date for neutral‐colored TPVs with an average visible transmittance (AVT) of 20%. These results demonstrate a scalable and cost‐effective method to advance TPV performance, paving the way for broader commercial applications of high‐efficiency, transparent solar technologies.