Synthesis of Cadmium Oxide/Si Heterostructure for Two-Band Sensor Application

Cadmium oxide on Si heterostructure device has been constructed using (111) oriented silicon substrate by reactive PLD technique. The deposition of CdO film was carried out by irradiating high-purity Cd target using Nd:YAG laser in the presence of reactive oxygen gas. The deposited tin films were characterized by the X-ray diffraction, scanning electron microscopy and AFM. The electrical properties of deposited films were investigated reaching to the optimum pressure of oxygen at which the device has been prepared. The films were polycrystalline in nature having high orientation along (111) (200) and (220) planes. The films are formed to give the lower value of the resistivity which was found to be 7.56 × 10⁻³ Ω cm at the ambient of oxygen pressure around 350 Torr and without using post-deposition heat treatment. The electrical properties such as current–voltage in dark and illumination and capacitance–voltage measurement were carried out and found to be directly related to the substrate temperature. Also, the detector parameters have been characterized by measuring responsivity and detectivity which are found to be 0.38 A/W and 3.9 × 10¹² cm Hz^1/2 W⁻¹, respectively.