Large-Area Transparent “Quantum Dot Glass” for Building-Integrated Photovoltaics

A concept of transparent “quantum dot glass” (TQDG) is proposed for a combination of a quantum dot (QD)-based glass luminescent solar concentrator (LSC) and its edge-attached solar cells, as a type of transparent photovoltaics (TPVs) for building-integrated photovoltaics (BIPVs). Different from conventional LSCs, which typically serve as pure optical devices, TQDGs have to fulfill requirements as both power-generating components and building construction materials. In this work, we demonstrate large-area (400 cm2) TQDGs based on silicon QDs in a triplex glass configuration. An overall power conversion efficiency (PCE) of 1.57% was obtained with back-reflection for a transparent TQDG (average visible transmittance of 84% with a color rendering index of 88 and a low haze ≤3%), contributing to a light utilization efficiency (LUE) of 1.3%, which is among the top reported TPVs based on the LSC technology with similar size. Most importantly, these TQDGs are shown to have better thermal and sound insulation properties compared to normal float glass, as well as improved mechanical performance and safety, which significantly pushes the TPV technology toward practical building integration. TQDGs simultaneously exhibit favorable photovoltaic, aesthetic, and building envelope characteristics and can serve as a multifunctional material for the realization of nearly zero-energy building concepts.