Process for producing a solar cell by means of epitaxial growth process

Claim 1

A process for producing a solar cell, said process comprises the steps of: forming a non-single crystal semiconductor layer, incorporating an impurity into said non-single crystal semiconductor layer to supersaturate said non-single crystal semiconductor layer with said impurity, forming an insulating layer on said non-single crystal semiconductor layer, annealing said non-single crystal semiconductor layer to enlarge crystal grains of said non-single crystal semiconductor layer to form an annealed polycrystalline semiconductor layer having enlarged crystal grains, forming laterally spaced openings in said insulating layer which expose the surface of said annealed polycrystalline semiconductor layer wherein the largest lateral dimension of the openings is less than the mean crystal grain size of said annealed polycrystalline semiconductor layer, performing crystal growth from each of said openings by a vapor phase crystal growing method to cause overgrowth of crystals grown over said insulating layer thereby forming a plurality of semiconductor single crystal growths with a crystal grain size which is greater than the means crystal grain size of said firstly formed annealed polycrystalline semiconductor layer, and forming an electrode over said plurality of semiconductor single crystal growths.