Upconversion-Assisted Dual-Band Luminescent Solar Concentrator Coupled for High Power Conversion Efficiency Photovoltaic Systems

Abstract

A luminescent solar concentrator (LSC)-based photovoltaic (PV) system, consisting of an LSC panel that harvests light and an edge-mounted solar cell that produces electricity using the photoluminescent light, is promising for semitransparent building-integrated photovoltaics (BIPVs). Here, we demonstrate a highly efficient and highly semitransparent LSC-PVs capable of harvesting dual wavelength bands. We used a triplet–triplet annihilation-based photon upconversion (UC) LSC that luminesce high energy green light by absorbing low energy red light, as well as downshift LSC that luminesce green light by absorbing ultraviolet light. The luminescent light concentrated from the two LSCs is absorbed by a dye-sensitized solar cell (DSSC) having a high extinction coefficient at this wavelength. Our optimized dual band LSC-PV exhibited 27% higher power conversion efficiency than the LSC-PV that absorb a single wavelength band. With respect to practical applications, the dual band LSC-DSSCs were fabricated in the form of an LSC window-DSSC window frame. We achieved a power conversion efficiency of 9.1% per LSC panel area. This dual-band LSC-DSSC exhibited high stability and maintained efficiency even at oblique illumination. Our results will be promising as an aesthetic and energy independent next generation BIPV.