In this study, the phosphotungstic acid /p-Si diode was fabricated by a drop coating method. The fabricated diode had excellent rectifying properties. The electrical properties of the diode were investigated in the temperature range of 50-400 K. The optical band gap of the phosphotungstic acid film was determined and found to be 3.66 eV. The electrical and photoresponse properties of an Al/p-Si-phosphotungstic acid/Al photodiode were studied. The electronic parameters such as ideality factor (n), barrier height (ΦB) and series resistance (Rs) were found to be strongly temperature dependent.