Longitudinal Through‐Hole Architecture for Efficient and Thickness‐Insensitive Semitransparent Organic Solar Cells

Abstract Semi‐transparent organic solar cells (ST‐OSCs) have great potential for application in vehicle‐ or building‐integrated solar energy harvesting. Ultrathin active layers and electrodes are typically utilized to guarantee high power conversion efficiency (PCE) and high average visible transmittance (AVT) simultaneously; however, such ultrathin parts are unsuitable for industrial high‐throughput manufacturing. In this study, ST‐OSCs are fabricated using a longitudinal through‐hole architecture to achieve functional region division and to eliminate the dependence on ultrathin films. A complete circuit that vertically corresponds to the silver grid is responsible for obtaining high PCE, and the longitudinal through‐holes embedded in it allow most of the light to pass through,where the overall transparency is associated with the through‐hole specification rather than the thicknesses of active layer and electrode. Excellent photovoltaic performance over a wide range of transparency (9.80–60.03%), with PCEs ranging from 6.04% to 15.34% is achieved. More critically, this architecture allows printable 300‐nm‐thick devices to achieve a record‐breaking light utilization efficiency (LUE) of 3.25%, and enables flexible ST‐OSCs to exhibit better flexural endurance by dispersing the extrusion stress into the through‐holes. This study paves the way for fabricating high‐performance ST‐OSCs and shows great promise for the commercialization of organic photovoltaics.