Light Absorption Enhancement In Thin-Film Silicon Solar Cell By Ag Nanoparticles On The Back

With the development of solar cell, how to improve the light absorption of solar cells has become the focus of attention. Apply metal nanoparticles to solar cell, surface plasmon paloriton produced by metal nanoparticles can enhance local resonance field and resonance forward scattering cross-section, thereby increasing light transmission path within solar cell, and then enhancing absorption of active medium, finally it can achieve the goal that enhancing absorption of solar cell.The structure of solar cell is placing array of cylindrical Ag nanoparticles on the back of solar cell, using Finite-Difference Time-Domain (FDTD) on simulating light absorption gain of this structure, we simulate the effect of radius and period of nanoparticle on light absorption gain. We conclude that when the thickness of silicon substrate equals500nm, the height of nanoparticle is100nm, radius equals350nm, the area of a circle of nanoparticle to unit square area ratio is0.785, the maximum of light absorption gain is1.522. Whereafter, there is a SiO2spacer layer between silicon substrate and Ag nanoparticle array. By simulating effect of different thickness of SiO2spacer layer on light absorption gain, we can conclude that when the thickness of silicon substrate equals500nm, the height of nanoparticle is100nm, radius equals100nm, the area of a circle of nanoparticle to unit square area ratio is0.5, the maximum of light absorption gain is1.618.