Study On Absorption Characteristics Of Solar Cells Based On Semiconductor Nanowire Structure

This thesis have studied the semiconductor nanowires,perovskite nanofilms,and tapered nanostructures,in order to optimize the design parameters of various semiconductor structures for improving solar cell efficiency and performance.The solar cell models of In As quantum dot embedded nanowire structure,perovskite thin film structure and cone-shaped perovskite structure with metallic Ag particles embedded on ZnO substrate have studied,and the following results are obtained:First,the effect of structural parameters of In As quantum dot nanowires on light absorption was systematically studied for nanowire arrays.The results show that the light absorption of quantum dot nanowire arrays is greatly affected by the filling factor and the diameter of the nanowires.The optimized array structure has a significantly enhanced light absorption efficiency in the visible light range.Under the optimal parameter configuration,the light absorption efficiency of quantum dot array is significantly improved in the long wavelength range(l > 600nm).Second,a planar thin film structure with crystalline silicon and ZnO as substrate was proposed,and the effect of structural parameters on light absorption was systematically studied.The research results show that the light absorption performance of the flat film is greatly affected by the structure parameters.The final research results show that the embedded metal particles have the best absorption efficiency when the radius is 70 nm.The finite field time difference(FDTD)optical simulation software was used to simulate the local field of the planar thin film structure.It was found that the embedded Ag particles can induce a very strong electromagnetic(EM)field at long wavelengths.It further shows that the embedded metal particles are beneficial to improve the light absorption capacity of the perovskite material in the long wavelength band.Finally,a perovskite nanocone model with crystalline silicon and ZnO as the substrate was designed,and the influence of the diameter and height of the metal particles on the optical characteristics of the structure was analyzed.The results showthat the absorption efficiency of the cone-shaped perovskite is greatly affected by the diameter and height of the metal particles.A systematic analysis was conducted in order to explore the trapping mechanism of enhanced light absorption.The final results show that the embedded metal particles in the flat film structure and the cone structure can improve the light absorption capacity of the perovskite material to a certain extent.The final optimized parameters: the height of the nanocones is 700 nm,and the radius of the Ag particles is 80 nm.