Performance Improvement of Thin-Film Solar Cells Using 1D Photonic Structures Optimized by Genetic Algorithm
Abstract
Abstract In this paper, the performance of thin film silicon solar cells is enhanced by employing 1D light-trapping structures. In order to design a structure which efficiently traps light, we have selected MgF2 and Al0.9Ga0.1As materials as the photonic crystal layers due to their negligible extinction coefficient within the silicon sunlight absorbing wavelength range. We have used a genetic algorithm for designing a back-reflector in order to increase the light absorption in the silicon layer. This increases the photocurrent of the solar cell and consequently, leads to an increased efficiency in the device. We have shown that an optimized 1D light-trapping structure can considerably enhance the efficiency of a thin-film silicon solar cell from 7.73% to almost 12%. This confirms the capability of properly designed 1D structures to improve the performance of solar energy conversion devices.