Synergistic approach of energy generation and conservation in buildings exploiting semitransparent organic photovoltaic windows globally

Abstract

Semitransparent organic photovoltaic (ST-OPV) windows have emerged as a promising solution for sustaining renewable energy and enhancing energy efficiency in buildings, for their ability to provide natural lighting while simultaneously generating electricity. However, the building field lacks a unified and comprehensive framework to guide the selection of materials and structural design for ST-OPVs in building envelopes, especially windows. To address this gap, this work establishes a systematic screening framework for ST-OPV device structures, focusing on active layer materials, interface layer materials, and electrode thicknesses. Instead of solely focusing on enhancing light utilization efficiency (LUE), the screening process integrates conventional photovoltaic performance metrics such as power conversion efficiency (PCE) and average visible transmittance (AVT) with essential architectural indices, including color rendering index (CRI), thermal performance, and overall building energy efficiency, ensuring that the designed ST-OPV can be truly applied in real world. The results indicates that ST-OPVs based on the PM6:Y6 system with a wide-bandgap donor showing top-tier performance cannot meet building code requirements for exterior windows, while ST-OPVs using the PCE10–2F:Y6 system with a narrow-bandgap donor can be fabricated into fully code-compliant photovoltaic windows, providing energy-saving benefits in any climate zone worldwide. The correspondingly designed ST-OPV window demonstrates a U-factor of 0.654 W/m²K, a solar heat gain coefficient (SHGC) of 0.236, and an AVT/SHGC ratio of 1.356. Compared to conventional commercial windows, this ST-OPV window can achieve annual energy savings of 74.8–239.7 kWh/m² around the world, showcasing its potential for real-world energy-efficient building applications.