A method is disclosed for making semiconductor films from a eutectic alloy comprising a metal and a semiconductor. Through heterogeneous nucleation said film is deposited at a deposition temperature on flexible substrates, such as glass. Specifically said film is vapor deposited at a fixed temperature in said deposition temperature where said deposition temperature is above a eutectic temperature of said eutectic alloy and below a temperature at which the substrate softens. Such films are nearly to entirely free of metal impurities and have widespread application in the manufacture and benefit of photovoltaic and display technologies.