Optical absorption enhancement in silicon square nanohole and hybrid square nanowire-hole arrays for photovoltaic applications

In this paper, the optical properties of the silicon square nanohole (SiSNH) arrays are theoretically studied via simulation based on the Rigorous Coupled Wave Analysis (RCWA) in detail. The ultimate efficiency of the optimized SiSNH arrays based solar cell is up to 25.14%, 81.65% higher than that of a Si thin film solar cell with equal thickness. In addition, the hybrid silicon square nanowire-hole (HSiSNWH) arrays is designed and studied in this work. Compared to SiSNH arrays, the ultimate efficiency trend of HSiSNWH arrays increases promptly or degrades slowly due to the additional resonances, as the filling ratio of SiSNH arrays is varied from 0.20 to 0.70. Moreover, the calculation indicates that the ultimate efficiency of HSiSNWH arrays based solar cell is higher than that of the corresponding SiSNH arrays with proper nanohole width (NHW) and filling ratio of Si.