LIGHT TRAPPING FOR THIN-FILM SILICON SOLAR-CELLS FABRICATED ON INSULATOR

We have developed a new solar cell using thin-film silicon supported b y a silicon substrate etched in a grid form. The light-trapping struct ures 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 m echanical strength and to minimize the electrical power loss, taking a ccount of the current flow path. A conversion efficiency of 14.2% for a practical size of 10 x 10 cm(2) is obtained by applying these calcul ated parameters using a single-crystal silicon substrate.