Zero-Dimensional Perovskite Nanocrystals for Efficient Luminescent Solar Concentrators

Luminescent solar concentrators (LSCs) are able to efficiently harvest solar energy through large-area photovoltaic windows, where fluorophores are delicately embedded. Among various types of fluorophores, all-inorganic perovskite nanocrystals (NCs) are emerging candidates as absorbers/emitters in LSCs due to their size/composition/dimensionality tunable optical properties and high photoluminescence quantum yield (PL QY). However, due to the large overlap between absorption and emission spectra, it is still challenging to fabricate high-efficiency LSCs. Intriguingly, zero-dimensional (OD) perovskites provide a number of features that meet the requirements for a potential LSC absorber, including i) small absorption/emission spectral overlap (Stokes shift up to 1.5 eV); ii) high PL QY (>95% for bulk crystal); iii) robust stability as a result of its large exciton binding energy; and iv) ease of synthesis. In this work, as a proof-of-concept experiment, Cs4PbBr6 perovskite NCs are used to fabricate semi-transparent large-area LSCs. Cs4PbBr6 perovskite film exhibits green emission with a high PL QY of approximate to 58% and a small absorption/emission spectral overlap. The optimized LSCs exhibit an external optical efficiency of as high as 2.4% and a power conversion efficiency of 1.8% (100 cm(2)). These results indicate that OD perovskite NCs are excellent candidates for high-efficiency LSCs compared to 3D perovskite NCs.