Light Trapping for Thin-Film Silicon Solar Cells Fabricated on Insulator

Abstract

We have developed a new solar cell using thin-film silicon supported by a silicon substrate etched in a grid form. The light-trapping structures of this cell have been studied by considering rear surface light reflections, electrical power loss and mechanical strength. High rear reflectance can be obtained by employing a multi-layer rear electrode. The pattern of the rear substrate is designed to provide sufficient mechanical strength and to minimize the electrical power loss, taking account of the current flow path. A conversion efficiency of 14.2% for a practical size of 10×10 cm 2 is obtained by applying these calculated parameters using a single-crystal silicon substrate.