Modeling of Solar Cell Efficiency Improvement Using Pyramid Grating in Single Junction Silicon Solar Cell

Abstract

In order to manipulate light in more effective ways than conventional optical materials to convert extra and cheap electrical energy from the sunlight we focused on surface and backside of solar cells. At first this paper concentrate on solar cell performance enhancement by introducing pyramids at the top of the wafer based crystalline silicon solar cells. The optimization of used pyramids as well as their height and width were performed. The efficiency of 24.45 % has been obtained for a cell (thickness of 50 µm) with surface pyramids, while efficiency of 19.53 % has been obtained for flat surface cell. Simulation results show improvement of performance when pyramids are used. Then we will focus on thickness reduction by manipulating the backside of the cell. Reducing the overall cost per watt is thus one of the major goals of this paper. As the thickness of the absorbing region is reduced, however, the absorption significantly decreases at energies close to the electronic bandgap of the semiconductor. This is particularly a problem for thin-film silicon cells. Devices based on crystalline silicon have poor absorption near the bandgap. Light trapping schemes are thus needed to enhance light absorption. In this paper light trapping is achieved using a micron-sized pyramidal surface texture and backside filters that causes scattering of light into the solar cell over a large angular range, thereby enhance the effective light path length. So this paper investigated the use of antireflection coating and back reflectors to improve thin film solar cell performances. Finally, efficiency of upper than 24 % is obtained for 8 µm thin film silicon cell with rear side filter.