Modeling‐Guided Design of Semitransparent Organic Photovoltaics with Improved Energy Harvesting and Saving Capabilities

Abstract Integrating semitransparent organic photovoltaics (ST‐OPVs) into building structures is a promising technology that serves aesthetic purposes while retaining window functionality, and it also facilitates solar energy harvesting and heat insulation. However, balancing power conversion efficiency (PCE), visible light transmittance (VLT), infrared radiation rejection (IRR), and color rendering index (CRI) for window applications remains a significant challenge. In this study, ST‐OPVs are developed that feature innovative near‐infrared‐absorbing materials. These devices are further coupled with an optical layer optimized through high‐throughput optical modeling to fine‐tune and enhance the different properties of the ST‐OPVs. Specifically, ST‐OPVs are achieved with a VLT of over 30%, a PCE of 12.5%, an IRR of over 90%, and a CRI of over 80. Furthermore, higher PCE of over 14% and IRR of over 95% can also be achieved, demonstrating the tunability of these photovoltaic properties. These figures highlight the exceptional performance of specialized ST‐OPVs for window applications, demonstrating their dual function of generating electricity and energy saving. Additionally, simulations show that replacing traditional heat insulation films with the ST‐OPVs can reduce annual energy demand by up to 60%, using Hong Kong as an example, underscoring their significant potential in sustainable building‐integrated photovoltaic (BIPV) applications.