| 摘要 |
PROBLEM TO BE SOLVED: To obtain a photovoltaic element which is superior in reliability and efficiency at a low cost by forming the metal layer of a rear reflecting layer by using copper-magnesium alloy, wherein the magnesium concentration is specified. SOLUTION: This photovoltaic element has a rear reflecting layer, composed of a metal layer 102 and a transparent layer 103, a semiconductor layer 104 and a transparent electrode 108, on a substrate 101. Since dendrite crystals do not grow in copper-magnesium alloy, short-circuit which is to be generated in a photovoltaic element used under severe environments can be prevented, and reliability can be improved. Magnesium is added to copper in the following range: at most 40at%, preferably 20-40at%, or more preferably 30-35at%. The reflectivity to a light of 700-1000nm is high and at least 90%, and the incident light can be effectively used, so that conversion efficiency of the photovoltaic element is improved. Further a uniform alloy film is obtained, a photovoltaic element having stable characteristics is obtained, and mass production is enabled at a low cost. |
