Monocrystalline silicon films are formed on patterned, metal-masked silicon substrates by a liquid-phase electro-epitaxial lateral overgrowth process. More specifically, silicon films are grown from liquid-metal solutions: (molten bismuth saturated with silicon) by current-induced crystallization on stripe-patterned, tungsten-masked (1 1 1) silicon substrates. Growth temperatures range from 800 degreesC to 1150 degreesC, and a current density of 2-20 A/cm(2) is imposed across the silicon/melt interface to effect growth. Continuous (over 1 cm(2) areas) epitaxial layers of silicon are achieved on tungsten-masked substrates patterned with 10-mum wide stripe openings spaced 100 mum apart. New types of solar cells and photodiodes, wherein the metal mask functions as a reflective "buried mirror" layer to increase optical coupling and internal quantum efficiency, are realized with this silicon liquid-phase electro-epitaxy process.