ABSTRACT
Bulk crystalline silicon (c-Si) solar cells (SCs) have dominated the photovoltaic market for years because of their abundant supply and high efficiency. However, large-scale commercial applications of Si-based photovoltaic cells is still an issue because of their high fabrication and material cost. Semiconductor nanostructures with sub-wavelength dimensions have shown excellent optical and electrical properties, which open a new pathway for a new generation of low-cost and high-efficiency SCs. Fabrication of high-efficiency nanostructure-based SCs requires the evaluation of the optimal geometric design of such systems theoretically. We perform optical as well as electrical simulations of gallium arsenide (GaAs) nanostructure-based SCs by using the finite-difference time-domain (FDTD) method. The influence of geometric parameters like base/diameter size and filling factor (base-size to period ratio) has been thoroughly analyzed and optimized to realize maximum optical absorption and short-circuit current density (Jsc). In comparison to planar conventional SCs' structure, nanostructure-based SCs have shown superior anti-reflection and light-trapping properties, which results in broad absorption spectra, high Jsc, and appreciable photogeneration rates. Finally, with the help of Lumerical charge solver module, we compute the J-V and P-V curves to obtain the complete set of photovoltaic parameters, such as electrical Jsc, Voc, fill factor (FF), and power conversion efficiency (PCE). We show that the GaAs nanostructure-based solar cell structure with optimized geometrical parameters achieves PCE of 28%, which is 1.65 times better than the conventional structure.
