Two-dimensional simulation of thin-film silicon solar cells with innovative device structures

✍ Scribed by M. Goldbach; Th. Meyer; R. Brendel; U. Rau

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 301 KB
• Volume: 7
• Category: Article
• ISSN: 1062-7995
• DOI: 10.1002/(sici)1099-159x(199903/04)7:2<85::aid-pip243>3.0.co;2-q

✦ Synopsis

We investigate the optical and electrical properties of thin-®lm silicon solar cells by means of numerical simulations. The optical design under investigation is the encapsulated-V texture, which is capable of absorbing sunlight corresponding to a maximum short-circuit current density of 35 mA cm À2 . Because the layer thickness can be restricted to only 4 m m m m mm, the encapsulated-V structure also provides a good collection eciency for photogenerated charge carriers. The results for our simulations suggest that practical eciencies above 12% can be expected for Si material with a minority carrier lifetime as low as 10 ns. Increased lifetimes of 100 ns allow for about 14% eciency. The bene®t of multiple junctions within the device structure strongly depends on surface recombination. The eciency of a single-junction cell can be improved by more the 3% absolute with a multi-junction device if the surface combination velocity is as high as 10 5 cm s À1 . For moderate surface recombination, the gain is only 1%.