The Influence of Boron Concentration on Electrical Properties of (a-Si:H:B)Thin Film

The Si:B materials have been deposited on glass substrate using plasma DC sputtering technique. The deposition process were performed with the following process parameters: the deposition time, gas pressure and substrate temperature with the aim to obtain a reasonable conductance as the solar cell material of (a-Si:H:B) thin film. The target was silicon material which was mixed by boron with concentration (0.1; 0.3; 0.5; 0.7) % weight. Variations of deposition time were (0.5 - 2) hour, gas pressure (1.1 x 10-1 - 1.4 x 10-1) Torr and substrate temperature (150 - 300) oC, while the hydrogen gas was kept constants at 4 sc cm during deposition. The resistance measurement has been done by four-point probe and the conductance was calculated using mathematic formulation. The results indicates that the minimum resistance of (a-Si:H:B) thin film was R = 2.73 x 108 Ω, this was achieved at deposition time of 1.5 hours, gas pressure 1.4 x 10-1 Torr and substrate temperature 200 oC. It could be concluded that the above process parameter is an optimum parameter for depositing the (a-Si:H:B) thin film. (author)