A Schottky diode based on an organic semiconductor 9-[(5-nitropyridin-2-aminoethyl) iminiomethyl]-anthracene (NAMA) was fabricated on n-Si using a spin-coating technique. The current-voltage (I-V) measurements of Au/NAMA/n-Si/In were taken under dark and various illumination levels to investigation of the change in electrical and photoresponse characteristics such as ideality factor, barrier height and series resistance with illumination. Reverse bias saturation current (I 0), ideality factor (n), and barrier height (Φ B ) values were found as 6.43 10-8 A, 3.54 and 0.756 eV in dark (low region); and 2.17 10-10 A, 1.39 and 0.903 eV under 100 W illumination level (low region). The forward bias semi logarithmic (I-V) characteristics showed two current-transport mechanisms acting in the diode. It has been shown that all electrical parameters are sensitive to illumination. The current-transport mechanisms of the prepared diode was examined by using ln(I F ) vs ln(V F ) and ln(I R )-V R 1/2 plots. Moreover, Au/NAMA/n-Si diode showed good photovoltaic performance that shows that the fabricated diode can be used as a photodiode in optoelectronic applications.