Reduction of the boron cross-contamination for plasma deposition of p–i–n devices in a single-chamber large area radio-frequency reactor

In this article, a new treatment to reduce boron contamination of the interface between the p- and i- layer is presented. An ammonia flush, performed at 10 Pa for 1 min, after deposition of the p-layer considerably reduces the boron contamination at the p–i interface of amorphous silicon p–i–n solar cells prepared in a single-chamber reactor. This treatment avoids the need to move the substrate out of the reactor during the full deposition process of a solar cell, thereby reducing costs. The measurement of boron contamination depth profile in the i-layer was done by Secondary Ion Mass Spectroscopy and the effectiveness of the treatment was supported by quantum efficiency and I–V measurements of solar cells.