Solution of efficiency loss in thinned silicon PERC solar cells

It is predicted that crystalline silicon passivated emitter and rear contact (c-Si PERC) solar cells will reach 70% global market share with the cell thickness decreased to 150 μm within next 7 years. It is of critical importance to address efficiency loss in order to deliver high cost-effective thinned Si cells. Herein, we not only address the efficiency loss but also acquire an extra gain for 150 μm-thick cells via optical and electrical designs. By rear design of SiNx/SiOx film, light absorption loss at longer wavelengths is made up. Via front design of SiO2/SiNx/SiOx film, light absorption at short wavelengths is enhanced and simultaneously, open circuit voltage (Voc) is considerably improved. Compared with standard 180 μm-thick cells, the present design experimentally lead to average short circuit current density (Jsc) increase by 0.2 mA/cm2 and average Voc improvement by 9 mV. Compared with standard thick cells and un-designed 150 μm-thick cells, net absolute efficiency gains are up to 0.4% from 22.0% to 22.4% and 0.6% from 21.8% to 22.4%, respectively. Device simulations are conducted to explain the experimentally observed improvements. The present study demonstrates a technical solution to address the efficiency loss in the thinned c-Si PERC cells.

China Three Gorges University, and many more

W. S. Yan and X. Y. Tan and L. Guan and H. P. Zhou and X. B. Yang and P. Xiang and Z. C. Zhong

Renewable Energy

Device simulations,Efficiency enhancement,Optical and electrical designs,Passivated emitter and rear contact (PERC),Photovoltaics,Silicon

2021

3

10.1016/j.renene.2020.10.134

18790682

118-124

Elsevier Ltd

165