Uniform 3D hydrothermally deposited zinc oxide nanorods with high haze ratio

We present low cost hydrothermally deposited uniform zinc oxide (ZnO) nanorods with high haze ratios for the a-Si thin film solar cells. The problem of low transmittance and conductivity of hydrothermally deposited ZnO nanorods was overcome by using RF magnetron sputtered aluminum doped zinc oxide (ZnO:Al ~300nm) films as a seed layer. The length and diameters of the ZnO nanorods were controlled by varying growth times from 1 to 4h. The length of the ZnO nanorods was varied from 1 to 1.5µm, while the diameter was kept larger than 300nm to obtain various aspect ratios. The uniform ZnO nanorods showed higher transmittance (~89.07%) and haze ratio in the visible wavelength region. We also observed that the large diameters (>300nm) and average aspect ratio (3–4) of ZnO nanorods favored the light scattering in the longer wavelength region. Therefore, we proposed uniformly deposited ZnO nanorods with high haze ratio for the future low cost and large area amorphous silicon thin film solar cells.