Diamond-Shaped Nanowires Solar Cell for Light Absorption Enhancement

In this study, a diamond Si nanowires (D-SiNWs) solar cell (SC) is proposed and numerically examined. Such recommended structure offers multiple light scattering laterally between the NWs. Further, the material filling ratio is reduced with broadband mode resonances over large wavelength range. Consequently, the transmission and reflection are lessened, hence the absorption is increased. The optical study is examined using the finite difference time domain (FDTD) technique. The electric field distribution of the studied structure shows a worthy light trapping relative to the conventional cylindrical-shaped NWs design. The light absorption enhancement is related to the improved Bloch-based modes associated with periodic structure. The reported NWS SC achieves an optical-current density <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\mathrm{J}_{\text{ph}})$</tex> of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$26.2\ \text{mA}/\text{cm}^{2}$</tex> and an optical-ultimate efficiency <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\eta)$</tex> of 29.7%, demonstrating enhancements of 9.5% and 69% compared to conventional cylindrical NWs and planar designs, respectively. This study demonstrates that the proposed NW structure not only reduces silicon material usage, thereby lowering production costs, but also significantly improves the optoelectronic performance of the solar cell. As a result, the recommended D-NWs structure offers better optical performance with less Si-material consumption where the production cost may be reduced