Solar cell

摘要

Disclosed herein is a solar cell which is composed basically of a first semiconductor layer of first conductivity type, a second semiconductor layer of second conductivity type, and a third semiconductor layer formed between them. The third semiconductor layer has a band gap narrower than that of the first and second semiconductor layers. The third semiconductor layer also has a pn junction therein. The semiconductor layers are each separated by a buffer layer in which the composition changes gradually across the thickness so that the lattice mismatch between the semiconductor layers is relieved.