Influence of In2O3:SnO2 films at different sputtering power on efficiency and stability of heterojunction solar cells

Tin-doped indium oxide (ITO) thin films were prepared at low substrate temperature by direct-current magnetron sputtering technology and applicated as the electrode of silicon heterojunction solar cells (HJT). The chemical, electrical and optical properties of ITO films deposited at different sputtering power are investigated. The optimized ITO films are applied as electrode of HJT solar cells, and the conversion efficiency of more than 25.22% is obtained. In addition, the passivated degradation resulting from ITO deposition is analyzed. The result shows that the degradation is recovered by the annealing process. Finally, the degradation of solar cell efficiency in dark nitrogen environment is tracked. It is found that the solar cells with the highest average conversion efficiency have poor stability, which is mainly attributed to the degradation of the fill factor.