Comparative study on IWO and ICO transparent conductive oxide films prepared by reactive plasma deposition for copper electroplated silicon heterojunction solar cell

Reactive plasma deposition (RPD) was utilized to prepare W-doped In2O3 (IWO) and Ce-doped In2O3 (ICO) transparent conductive oxide (TCO) films for fabricating the copper electroplated silicon heterojunction (C-HJT) solar cell. TCOs with high carrier mobility (μe) and low carrier concentration (Ne) are preferred for the solar cell to limit the photocurrent loss induced by the possible free carrier absorption in TCOs. The electrical and optical properties of the IWO and ICO films were optimized via adjusting the RPD process conditions. As a result, both IWO and ICO films presented higher μe and lower Ne than the Sn-doped In2O3 (ITO) control prepared by magnetron sputtering. Especially, the ICOs could achieve much higher μe. When an optimized ICO with μe of up to 101.7 cm2/V s was applied on the back side of the C-HJT solar cell, about 0.5% relative enhancement for the efficiency of the solar cell was achieved. The superior electrical and optical properties of ICO films are conducive to the improvement of cell efficiency.