Zinc oxide as an active n-layer and antireflection coating for silicon based heterojunction solar cell

We report a single heterojunction solar cell model based on crystalline p-silicon and n-zinc oxide. The ZnO can act as front n-layer as well as antireflection coating saving processing cost and complexity. Experiments are performed to find optimized growth window using MOCVD to achieve maximum transmission in ZnO as front layer of the solar cell. Gallium-rich ZnO:Ga films are also grown to improve optical properties of the front layer. Optical characterizations of pristine ZnO and gallium-rich ZnO:Ga are presented. The modified PC1D software is used to find the optimized parameters for the solar cell. Absorption spectrum of ~0.5 µm thick ZnO film grown in our lab was used in the simulations to get realistic results. Simulations anticipated conversion efficiency of 19% and fill factor of 81%.