Photoelectric conversion element and power generation system using the same

摘要

The present invention provides a photovoltaic element in which the open-circuit voltage and the path length of holes are improved by preventing the recombination of photoexcited carriers. The p-i-n junction type photovoltaic element is composed of a p-type layer, an i-type layer of a laminated structure consisting of an i-type layer formed by RF plasma CVD on the p-type layer side and an i-type layer formed by microwave ( mu W) CVD on the n-type layer side, or an i-type layer formed by microwave ( mu W) plasma CVD on the p-type layer side and an i-type layer formed by RF plasma CVD on the n-type layer side, characterized in that the i-type layer formed by mu W plasma CVD is formed by a process in which a lower mu W energy and a higher RF energy than the mu W energy needed to decompose 100% of the source gas are simultaneously applied to a source gas containing Si and Ge at a pressure of 50 mTorr or less, such that the minimum value of the bandgap is shifted toward the p-type layer side, away from the center of the i-type layer, and the i-type layer formed by RF plasma CVD is formed 30 nm thick or less by using a source gas containing a silicon-containing gas at a deposition rate of 2 nm/sec or less.