Optimised antireflection coatings for planar silicon solar cells using remote PECVD silicon nitride and porous silicon dioxide
✍ Scribed by Henning Nagel; Armin G. Aberle; Rudolf Hezel
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 210 KB
- Volume
- 7
- Category
- Article
- ISSN
- 1062-7995
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✦ Synopsis
Silicon nitride (SiN) ®lms fabricated by remote plasma-enhanced chemical vapour deposition (RPECVD) have recently been shown to provide an excellent electronic passivation of silicon surfaces. This property, in combination with its large refractive index, makes RPECVD SiN an ideal candidate for a surface-passivating antire¯ection coating on silicon solar cells. A major problem of these ®lms, however, is the fact that the extinction coecient increases with increasing refractive index. Hence, a careful optimisation of RPECVD SiN based antire¯ection coatings on silicon solar cells must consider the light absorption within the ®lms. Optimal optical performance of silicon solar cells in air is obtained if the RPECVD SiN ®lms are combined with a medium with a refractive index below 1 . 46, such as porous SiO 2 . In this study, the dispersion of the refractive indices and the extinction coecients of RPECVD SiN, porous SiO 2 , and several other relevant materials (MgF 2 , TiO x , ZnS, B270 crown glass, soda lime glass, ethylene vinyl acetate and resin as used in commercial photovoltaic modules) are experimentally determined. Based on these data, the shortcircuit currents of planar silicon solar cells covered by RPECVD SiN and/or porous SiO 2 single-and multi-layer antire¯ection coatings are numerically maximised for glass-encapsulated as well as non-encapsulated operating conditions. The porous SiO 2 /RPECVD SiN-based antire¯ection coatings optimised for these applications are shown to be universally suited for silicon solar cells, regardless of the internal blue or red response of the cells.