Simulation of Boosting Efficiency of GaAs Absorption Layers with KNbO3 Scatterers for Solar Cells

Abstract

In this work, gallium arsenide (GaAs), which has an adjustable band gap and low cost, was adopted as an absorption layer in which KNbO3, having good dielectric, photoelectric, and piezoelectric properties, served as a scattering element for the improvement in absorption efficiency of solar cells. Benefited by the high absorption efficiency of KNbO3, the utilization of the ultraviolet and infrared bands for solar cells can be strengthened. In addition, the ferroelectric and photovoltaic characteristics of KNbO3 enable the realization of decreased thickness of solar cells. Based on the simulation of the shape, width, and period of the scattering element, the effect of the thickness of the scattering element on the absorption efficiency, quantum efficiency, and total efficiency of absorption efficiency was comprehensively simulated. The results show that the absorption layer delivers the optimal performance when using a hexagonal KNbO3 scattering element. The absorption efficiency of the GaAs absorption layer with KNbO3 as the scattering element is increased by 28.42% compared with that of a GaAs absorption layer with empty holes. In addition, the quantum efficiency is maintained above 98% and the total efficiency is 91.59%. At the same time, the efficiency of such an absorption layer is still above 90% when the angle ranges from 0 to 70°. This work provides theoretical guidance for the rational design of solar cells based on photonic crystal structures.