Numerical analysis of field-effect surface passivation for solar cells

✍ Scribed by H. Ohtsuka; T. Uematsu; T. Warabisako

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 905 KB
• Volume: 44
• Category: Article
• ISSN: 0927-0248
• DOI: 10.1016/0927-0248(96)00035-9

✦ Synopsis

In order to investigate the influence of surface potential on the electric characteristics of solar cells, the characteristics of conventional cells and back-contact type high-efficiency silicon cells were analyzed using 2-dimensional numerical simulation, varying the surface electrical potential.

The locations where surface electrical potential is controlled are the rear side in conventional cells and the front side in back-contact cells. As a result of the calculations, it was found that field-effect surface passivation yields cell characteristics equivalent to those of a cell with effective surface recombination velocity of 0 cm/s, even if the cell has a poor Si/SiO 2 interface (i.e., Dit > 1.0 )< 1011 cm -2 eV-1). It was also found that both the use of a higher resistivity wafer and --especially in p-type substrates --the formation of inversion layers causes the field-effect surface passivation to work the fullest effect. In addition, a computer simulation based on physical-parameter measurements taken from actual materials forecasts that a back-contact cell would realistically be able to exceed 25% efficiency under AM1.5 global, one-sun illumination.