Intermittent Very High Frequency Plasma Deposition on Microcrystalline Silicon Solar Cells Enabling High Conversion Efficiency

• Main Authors: Mitsuoki Hishida, Takeyuki Sekimoto, Mitsuhiro Matsumoto, Akira Terakawa
• Format: Article
• Language: English
• Published: MDPI AG 2016-01-01
• Series: Energies
• Subjects: thin-film silicon tandem solar cell; microcrystalline silicon; amorphous silicon; crystallinity; plasma-enhanced chemical vapor deposition; conversion efficiency
• Online Access: http://www.mdpi.com/1996-1073/9/1/42
• ISSN: 1996-1073

Stopping the plasma-enhanced chemical vapor deposition (PECVD) once and maintaining the film in a vacuum for 30 s were performed. This was done several times during the formation of a film of i-layer microcrystalline silicon (μc-Si:H) used in thin-film silicon tandem solar cells. This process aimed to reduce defect regions which occur due to collision with neighboring grains as the film becomes thicker. As a result, high crystallinity (Xc) of μc-Si:H was obtained. Eventually, a solar cell using this process improved the conversion efficiency by 1.3% (0.14 points), compared with a normal-condition cell. In this paper, we propose an easy method to improve the conversion efficiency with PECVD.