On thermal and optical sensor applications of chitosan molecule in the Co/Chitosan/p-Si hybrid heterojunction design

Co/Chitosan/p-Si/Al and Co/p-Si devices were made and barrier height and ideality factor values of both devices were determined at room temperature (dark conditions). After the chitosan interlayer was found to improve the device, the thermal and photosensivity properties of the Co/Chitosan/p-Si/Al device were investigated in detail. The current–voltage measurements of Co/Chitosan/p-Si/Al heterojunction were performed in temperature range of 100–460 K and illumination intensity range of 100–400 mW/cm 2 . It was seen that the device parameters such as barrier height, ideality factor, series resistance and interface states density were strongly dependent on temperature. Furthermore, the capacitance–voltage ( C–V ) characteristics of the device were investigated at various frequencies at room temperature. The responsivity ( R ), detectivity ( D *) and rectification ratio (RR) values of the Co/Chitosan/p-Si/Al heterojunction were found to be as a function of illumination intensity. The experimental results show that the fabricated device with chitosan thin film interlayer can be used in various optoelectronic applications, especially applications in low temperature switching devices, energy generation, photodiode and photodetector.