Enhanced Conversion Efficiency for Solar Cells With Periodic Grating of Nanowires

The absorption of an amorphous silicon thin film with periodic gratings formed by an array of nanowires with varied heights and different profile shapes is studied. Optimized parameters, including period, duty ratio, and the angle of unit cell and the shape of the profile, namely, tented, triangular, and concave type, are used to achieve the optimal results of light absorption and conversion efficiency. The enhancement of conversion efficiency occurs both in TE and TM polarizations. The photovoltaic conversion efficiency of the solar cell with triangular profile can be increased by 58.21%, 42.45%, and 20.38%, compared with those with flat surface, equal-thickness nanowires, and periodic triangular textures, respectively.