Electron beam-treated ZnO thin film as an anti-reflection layer for crystalline Si solar cells

ZnO thin films were deposited on crystalline Si (c-Si) solar cells as an electron transport and anti-reflection layer using a sol-gel spin-coating method. ZnO films exhibited optical transmittance in the visible region greater than 90%. When Ga was doped into the ZnO film, the electrical resistivity decreased with increasing carrier concentration. The solar cell efficiency improved with the addition of a Ga-doped ZnO thin film because of an increased current density (J_sc) fill factor (FF). Electron beam treatment decreased resistivity by increasing carrier concentration and mobility. Introduction of an electron beam onto the ZnO anti-reflection layer-coated c-Si solar cell increased the cell efficiency due to increases in J_sc and FF. The c-Si solar cell passivated by Ga doping and electron beam treatment revealed a 1.23% improvement in cell efficiency, resulting in a final 11.6% cell efficiency.