Crystalline silicon surface passivation by the negative charge dielectric film

Surface passivation is one of the key factors to the high efficiency solar cells. In this paper negative charge dielectric films (Al2O3)x(TiO2)1-x used as backside surface passivation for crystalline silicon solar cells were prepared by the low-cost sol-gel method. The relation between the passivation properties of the films and the preparation technology was investigated and optimized. The surface passivation characteristic of the alloyed (Al2O3)x(TiO2)1-x thin films are in correlation with sintering temperature. The surface recombination velocity of 1260 cm/s of the thin layers can be achieved at sintering temperature 400 °C. The alloyed dielectric films also have feasible optical properties which can be acted as backside reflector if combined with metal contact.