Broadband Cr3Â +/(Pr3Â +/Yb3Â +) quantum cutting down-conversion system doped in Y2O3/Y3Al5O12 heterostructure thin film

In this work, granular Y2O3/Y3Al5O12(YAG) heterostructure thin films with 100-200 nm holes on surface were fabricated by depositing metal yttrium on c-plane sapphire and subsequent thermal anneal. Such Y2O3/YAG thin films are excellent matrix for luminescent materials based on rare earth. Based on this matrix, a Cr3 +/(Pr3 +/Yb3 +) broadband down-converter was fabricated for improving the photovoltaic conversion efficiency of crystalline silicon solar cell (c-Si SC). Cr3 + was used to harvest the incident light and sensitize Pr3 +/Yb3 + quantum cutting (QC) couple. QC down-conversion to Yb3 + infrared emission was realized in the region of 230 nm to 500 nm, which approaches the maximum bandwidth of QC down-conversion for c-Si SC.