Excess Carrier Lifetime Improvement in c-Si Solar Cells by YAG:Ce$^{3+}$-Yb$^{3+}$
Talib Hussain1,2, Hui-Qi Ye1, Dong Xiao1**
1National Astronomical Observatories, Nanjing Institute of Astronomical Optics & Technology, Key Laboratory of Astronomical Optics & Technology, Nanjing Institute of Astronomical Optics & Technology, Chinese Academy of Sciences, Nanjing 210042 2University of Chinese Academy of Sciences, Beijing 100049
Abstract：Ce$^{3+}$-Yb$^{3+}$ doped Y$_{3}$A$_{l5}$O$_{12}$ (YAG) is a luminescent down-conversion material which could convert visible photons to near infrared photons. In this work, YAG:Ce$^{3+}$-Yb$^{3+}$ is applied on the front surface of mass-produced mono crystalline Si solar cells. For the coated cells, the external quantum efficiency from the visible to the near infrared is improved, and the energy conversion efficiency enhances from 11.70% to 12.2% under AM1.5G. Furthermore, the phosphor down-conversion effect on the solar cell is characterized by the microwave detected photoconductivity technique on the n-type silicon wafer under the 977 nm excitation. The down-conversion materials improve the average excess carrier lifetime from 22.5 μs to 24.2 μs and the average surface recombination velocity reduces from 424.5 cm/s to 371.6 cm/s, which reveal the significant reduction in excess carrier recombination by the phosphors.
2016, Vol. 33 
