Near-infrared quantum cutting in Eu3+-Yb3+ co-doped YAG through downconversion for silicon solar cell

Abstract

Near-infrared (NIR) quantum cutting (QC) could provide a solution to minimise the heat loss due to the thermalisation of electron-hole pairs in solar cells by converting high-energy photons to low-energy photons matching with the greatest spectral response of silicon solar cell. Europium (Eu3+) and ytterbium (Yb3+) co-doped yttrium aluminium garnet (Y3Al5O12, YAG) can be used as QC phosphor with emission in both visible and NIR regions. In this study, upon the excitation at 394 nm, the D-5(0)-> 4f(6) transition of Eu3+ is induced, the characteristic NIR emission located at 1030 nm due to the energy transfer between of F-2(5/2)-F-2(7/2) levels of Yb3+, is generated. The quantum efficiency (QE) was derived to be as high as 144%. The results showed the possibility for enhancing the photovoltaic conversion efficiency of silicon-based solar cell by modifying the absorption and utilising the energy in the UV-blue part of the solar spectrum.