Semi-transparent solar cells achieve record efficiency in new study

Researchers at The Hong Kong Polytechnic University (PolyU) have developed a novel parameter called FoMLUE (Figure of Merit for Light Utilization Efficiency) to evaluate and optimize photoactive materials for semi-transparent organic photovoltaics (ST-OPVs). This dimensionless metric integrates average visual transmittance, bandgap, and current density to identify the most effective material combinations for solar windows. Using ternary materials with the highest FoMLUE scores, the team achieved a record light utilization efficiency of 6.05% in semi-transparent solar cells, surpassing previous benchmarks. These advanced ST-OPVs also demonstrated improved thermal insulation and operational stability, making them promising candidates for building-integrated photovoltaics (BIPV), renewable energy vehicles, and agricultural greenhouses. ST-OPVs offer a unique balance of aesthetics and energy generation by allowing transparency or tinting, enabling their integration into everyday surfaces like windows and facades without compromising design or visibility. The PolyU team’s research highlights the potential for