MULTIPLE LAYER THIN FILM SOLAR CELLS WITH BURIED CONTACTS

摘要

A multilayer solar cell structure includes a stack of alternating p-type and n-type semiconductor layers (10, 11, 12, 13, 14) arranged to form a plurality of rectifying photovoltaic junctions (15, 16, 17, 18). Low-cost cells are manufactured from low-quality material which is optimized by employing very high doping levels in thin layers. Typically, the doping levels are greater than 10<17> atoms/cm<3>, and the thickness of the layers is related to carrier diffusion length in thickness. Contact is made to underlying layers by way of a buried contact structure comprising grooves extending down through all of the active layers, the walls of each groove being doped (33, 34) with n- or p-type impurities depending upon the layers to which the respective contact is to be connected and the grooves being filled or partly filled with metal contact material (31, 32).