Numerical simulation of highly photovoltaic efficiency of InGaN based solar cells with ZnO as window layer

Abstract

InxGa1-xN, as one promising nitride semiconductor alloys for modern optoelectronic devices, has received extensive attention in recent years. However, due to its powerful modulation of energy band gap from UV to visible spectra (0.7-3.4 eV) and its interesting absorption coefficient can range from 103 to 105 cm-1 , depending on the material properties, it can be considered as a potential candidate for high efficiency solar cells. The actual efficiency reached is (30.38%) [1]. In order to enhance more the efficiency, we perform in this work, a device modeling and numerical simulation using SCAPS software. We optimize the photovoltaic characteristics of a solar cell based on InxGa1-xN. This cell is mainly composed of indium gallium nitride semiconductors for both buffer and active layer p-InxGa1-xN/i-InxGa1-xN and the window layer contains of n-ZnO. The optimization of the various optoelectronic parameters allows improving performance of the solar cell, in addition to absorbing as much solar radiation as possible. The main photovoltaic parameters of the analog device: open circuit voltage, short circuit current density, fill factor and conversion efficiency (η) were compared and analyzed. We have reached the conversion efficiency of 26.11% for a thickness of 1450 nm and an n-doping of 3×1018 cm-3 in the active layer (In0.3Ga0.7N). This study investigates the great potential of InGaN solar cells and can be used for the design and manufacture of high efficiency III-nitride based solar cells.