Investigation of quasi-periodic structures to increase the efficiency of thin-film silicon solar cells: A comparative study

Abstract

To boost the energy conversion efficiency in a thin-film Si solar cell, the effect of applying simple and generalized Fibonacci and Thue-Morse quasi-periodic multilayers in the front and back sides have been investigated. The anti-reflection coating and the back reflector are composed of SiO2/TiO2 and SiO2/Si sequences, respectively and the obtained results are in a good agreement with previous studies. Also, a 2D square array photonic crystal with 12-fold basis has been introduced to enhance the optical path length and hence, the absorption probability for longer wavelengths due to excitation of higher-order diffraction modes. The study has been carried out using the transfer matrix method (TMM) and the finite difference time domain (FDTD) methods and the electrical characteristics have been obtained implementing the drift-diffusion. A reasonable enhancement of ~115% and more than 120% in the short circuit current density and conversion efficiency have been achieved, respectively in the optimized structure.