Modeling and analysis of grating structure for enhancing the absorbance in InGaN-based solar cell

Good light trapping is essential to make high efficiency InGaN-based solar cells. As InGaN wafers are being made increasingly, thinner, light trapping becomes even more important. In this study, we propose a structure of one-dimensional InGaN grating for the InGaN-based solar cells is proposed. The solar energy absorption characteristics of this structure are studied by the the Finite element method (FEM) method. By alternately altering the grating depth and the filling factor, a new type of grating structure is proposed. For such a structure, different gratings are studied. Numerical computation shows that the absorptance of the InGaN grating structure is over 0.88 throughout the entire computational band. The optimum parameters of the proposed structure are period (a = 480 nm), a filling factor (ff = 50 %) and depth (d=210 nm), which indicates the proposed structured surface may have potential applications in solar cells manufacturing.