Influence of front contact work function on silicon heterojunction solar cell performance

In this study, we present numerical and experimental analyses of the effect of the work function of the transparent conducting oxide (TCO) on the performance of silicon heterojunction solar cells. The simulation results showed that the solar cell performance such as Voc and FF were strongly affected by the work function of TCO films due to band bending. The experimental analysis was carried out by preparing Zn–In–Sn–O films with varying work function by varying the composition. The compositional dependence of the work function, optical and electronic properties of Zn–In–Sn–O films was examined, and the performance of the silicon heterojunction solar cells with corresponding TCO films was analyzed. The electrical properties and work function in Zn–In–Sn–O films were significantly influenced by Zn content, and Zn–In–Sn–O film with 12.7 at.% Zn content, which had the highest work function and lowest resistivity among the studied films, resulted in the highest conversion efficiency of solar cell due to increased Voc and FF. It was shown that the behavior of performance parameters in silicone heterojunction solar cells closely correlated with the work function and electrical properties of TCO films.

► The film with 12.7 at.% Zn content showed the highest electrical properties and work function.
► Voc and FF follow similar behavior to the work function.
► The highest conversion efficiency of 17.7% was obtained from the solar cell having Zn–In–Sn–O film with 12.7 at.% Zn content.