A highly transparent and efficient luminescent solar concentrator based on nanosized molybdenum clusters and quantum-cutting perovskite nanocrystals

Abstract

A luminescent solar concentrator (LSC) is a photovoltaic (PV) device that uses luminophores embedded in waveguides to absorb and concentrate emitted solar energy to produce electricity. The most crucial factors enhancing the power conversion efficiency (PCE) of the LSC are high photoluminescence quantum yield (PLQY), low reabsorption, and low scattering of luminophores in a waveguide. We used a highly emissive molybdenum cluster anion, [Mo₆I₈(CF₃COO)₆]²⁻, as a luminophore with a large Stokes shift to reduce reabsorption and scattering loss, and used quantum-cutting perovskite, Yb³⁺-doped CsPbCl₃ nanocrystals, as a secondary luminophore with a high PLQY well over 100%. This dual-dye embedded LSC waveguide exhibited strong absorption in the ultraviolet region up to ∼450 nm and emissions at 670 nm and 980 nm. The emission wavelengths of luminophore matched well with that of the external quantum efficiency (EQE) wavelength range of Si PV cell attached to the edge of the LSC waveguide, and its transparency could be utilized as highly efficient building-integrated photovoltaics (BIPV). LSCs with a PCE of 1.96% and an average visible transparency (AVT) of 68% and with a PCE of 1.62% and an AVT of 80% were fabricated. Our highly efficient and transparent LSCs are chemically stable and robust enough to be used as promising photovoltaic windows to realize zero-energy buildings.