In this article, we have studied contact between indium tin oxide (ITO) and n-type silicon. First, the characteristics of ITO thin films have been identified. The films have high transparent and low resistivity (∼88 % of transmittance and 2.8×10<sup>-3</sup> Ω-cm). Fabrication of the ITO/n-Si photodetector was presented which was ITO thin layer deposited on 10 Ω-cm resistivity silicon wafer by R.F. sputter method. Finally, a study of characteristics of the photodetector such as I-V characteristics, C-V characteristics, and frequency response has been done. The photodetectors have built in voltage (V<inf>bi</inf>) about 0.26 V, the dark current of 5 μA and light current of 1.5 mA at 25,000 lux, 5V. Capacitance and frequency response are about 110 pF and 120 kHz, respectively.
