Tóm tắt

The palladium sulfide/p-type Si (PdS/p-Si) heterojunction was used to investigate the effects of gamma rayrnexposure on the structural, optical and current-voltage (I–V) characteristics, for gamma detection. High-qualityrnPdS thin films was deposited onto p-Si substrates and evaluated as active components of the heterojunction. ThernPdS thin films was prepared using a successive ionic layer adsorption and reaction (SILAR) technique. Thernsamples were then irradiated using a60Co gamma source at dose of up to 100 kGy. X-ray diffraction (XRD)rnanalysis indicated the formation of a tetragonal phase in the PdS thin films, an increase in crystallinity and arndecrease in the crystallite size. The distributions of spherical grains on the surfaces of the substrate were observedrnusing a field emission scanning electron microscope (FE-SEM) and energy dispersive X-ray (EDX) analysis wasrnperformed to determine the stoichiometric compositions of the PdS thin films. The FE-SEM images revealed thernpresence of voids after irradiation. Photoluminescence (PL) spectroscopy indicated an increase in the recombirnnation rate of electron-hole pairs after irradiation, and spectral broadening occurred as a function of the gammarndose. The I–V characteristics of the PdS/p-Si heterojunction were investigated before and after irradiation.rnChanges in the electrical properties of the heterojunctions induced by irradiation, including the saturationrncurrent, ideality factor, barrier height, series resistance and shunt resistance, were investigated. The linearrnelectrical responses of the PdS/p-Si heterojunction indicated that they were highly sensitive to gamma radiation.rnThe outstanding electrical and optical responses of the PdS/p-Si heterojunction in accordance with the gammarndose indicated that they could be used for radiation dosimetry.