Heterojunction SnO2 : As/n-Si (Textured) solar cells were fabricated by chemical vapour deposition of arsenic doped tin oxide films over textured n-type single-crystal silicon substrate of resistivity 0.1 OMEGA-cm. The performance of the solar cell has been analysed by measuring current density vs voltage characteristics under dark and illumination. A solar cell of area 2.0 cm2 shows a conversion efficiency 12.6%, open circuit voltage 0.45 V and fill factor 0.70 at 300 K under AM1 simulated radiation. The dark current are controlled by a combination of thermionic emission and diffusion processes. The capacitance-voltage characteristics measured at 1 kHz frequency shows the abrupt nature of the junction with a built-in voltage V(d) = 0.56 V. The variation of cell parameters with temperature has been also studied.