Abstract: This invention is a photovoltaic device comprising an intrinsic or i-layer of amorphous silicon and where the photovoltaic device is more efficient at converting light energy to electric energy at high operating temperatures than at low operating temperatures. The photovoltaic devices of this invention are suitable for use in high temperature operating environments.

Abstract: A photovoltaic device comprising an amorphous silicon-containing i-layer that is more efficient at elevated operation temperatures than at lower operation temperatures.

Abstract: Alloys of amorphous silicon with Group VIa elements are disclosed that form high-quality materials for photovoltaic cells that are resistant to Staebler-Wronski photodegradation. Also disclosed are methods for manufacturing the alloys. The alloys can be formed as films on solid-state substrates by reacting silane gas and at least one alloying gas (H.sub.2 M, wherein M is an element from Group VIa of the periodic table), preferably with hydrogen dilution, by a glow-discharge method such as plasma-enhanced chemical vapor deposition. The alloys can have an optical bandgap energy from about 1.0 eV to about 2.3 eV, as determined by selecting one or more different Group VIa elements for alloying or by changing the concentration(s) of the alloying element(s) in the alloy. The alloys exhibit excellent light-to-dark conductivity ratios, excellent structural quality, and resistance to Staebler-Wronski degradation. They can be used as "i" type or doped for use as "p" or "n" type materials.