Enhanced optical properties in inclined GaAs nanowire arrays for high-efficiency solar cells

• This paper presents a systematic study on high-efficiency solar cells consisting of inclined GaAs nanowire arrays (NWAs) structure as light trapping layer. Through simulation, we find out that: Light absorption of inclined NWAs is highly sensitive to the structure parameters.
• Inclined NWAs displays a better optical performance compared with vertical NWAs.
• The optimized inclined NWAs can absorb more than 90% of above-bandgap sunlight.
• A higher photocurrent of 30.3 mA/cm2 can be yielded by this optimized structure.
• This NWAs structure will be a promising solution for light absorption enhancement.

The inclined Gallium Arsenide (GaAs) nanowire arrays (NWAs) as light absorbing structures for solar photovoltaics are proposed. The influence of geometric parameters on the optical absorption properties is systematically investigated, and the optimal geometric parameters of the proposed structure are determined by using rigorous coupled wave analysis (RCWA) and the finite element method. It is found that the absorption efficiency of the optimized structure can be improved significantly compared with vertical NWAs and thin film layer structure. The optimized structure yields a photocurrent of 30.3 mA/cm2, which is much higher than that of vertical NWAs and thin film layer with the same geometric configurations.