Surface passivation of nano-textured silicon solar cells by atomic layer deposited Al2O3 films

In the work, the surface recombination of silicon nanostructures was investigated. Silicon nanostructures were synthesized using technique of silver catalyzed chemical wet etching, and the passivation layers of SiNx and Al2O3 were deposited on the samples. The thermal atomic layer deposited Al2O3 can conformally cover the rough surface and reduce the defect density of the nanostructures. Moreover, the negative fixed charge in Al2O3 layer introduces the surface field effect passivation. The lifetime measurement result indicates that Al2O3 layers offer much better passivation effect on the silicon nanostructure surface than SiNx layers. The silicon nano-textured solar cells with SiNx and Al2O3 passivation layers were manufactured and measured. The results show that the enhanced solar cell performance was achieved by Al2O3 passivation. (c) 2013 AIP Publishing LLC.