Polycrystalline gallium arsenide films of 10‐&mgr;m thickness deposited on tungsten/graphite substrates by the reaction between gallium, hydrogen chloride, and arsine have been used for the fabrication of thin‐film homojunction solar cells. The major problem associated with polycrystalline gallium arsenide thin‐film cells is the grain‐boundary shunting effect. In order to prepare solar cells with conversion efficiency higher than 10%, gallium arsenide films with large grains are necessary. Unlike gallium arsenide, germanium films can be easily recrystallized to enhance the grain size. Thin‐film gallium arsenide solar cells of thep+/nconfiguration with an AM1 efficiency of about 10% have been prepared using recrystallized germanium and large‐grain germanium substrates.