Impact of gamma rays on the structural, optical, and current-voltage characteristics of CuPbI3/p-Si heterojunctions

Copper lead iodide (CuPbI3) perovskite thin films were spin-coated on p-type silicon (p-Si) substrates to manufacture CuPbI3/p-Si heterojunctions. A Co-60 gamma source has been used to examine the influence of gamma exposure doses of 0-100 kGy on the nanostructural, electrical, morphological, and optical, properties of the CuPbI3/p-Si heterostructure. The X-ray diffraction (XRD) consequences showed an enhancement in crystalline naturre and confirmed the hexagonal structure of the prepared thin films. Field emission scanning electron microscopy (FESEM) images revealed that the average grain size decreased (92-56 nm) up to 50 kGy, and the small particles agglomerated with a further increase in the gamma dose. The photoluminescence (PL) results of the deposited sample revealed only one broad bandgap peak. However, the PL spectra of the gamma rayexposed samples exhibited induced defect emission near the valence band edge. The I-V properties revealed the charge transportation mechanism in the heterojunction, and the impacts of different gamma exposure doses on the electrical characteristics of the fabricated CuPbI3/p-Si heterojunction were investigated. Electrical parameters, such as the barrier potential, saturation current, series resistance, and ideality factor (IF) of the CuPbI3/ p-Si heterostructure changed with the gamma irradiation dose owing to interfacial inhomogeneities, induced defect concentration, charge accumulation at the interface, and barrier thickness.