LAUSR

This paper presents the effect of doping concentration on the properties of PbI2 nanostructure film and p-PbI2:Ag/n-Si photodetector prepared by pulsed laser deposition PLD method. The PbI2 film was doped with silver at doping concentrations of 1%, 3% and 5%. XRD results show that all deposited PbI2 films are polycrystalline and well-crystallized along (001) plane with hexagonal structure. The structural studies revealed that the grain size of the film decreases as the doping concentration increase. Energy dispersive X-ray EDX, scanning electron microscope SEM and elemental mapping analysis confirm the presence of Pb, I and Ag elements and the films were near stoichiometric. Raman spectra of PbI2 film showed the presence of Raman peaks located at 73, 94.3, 108, 165.7, and 208.9 cm−1 corresponding to E21, A11, A12, 2E11 and 2A12 vibration modes, respectively, and a Raman peak at 185 cm−1 was observed for the film doped with 5 wt% which indexed to 2E11. The optical energy gap of the film decreased from 2.8 to 2.3 eV after doping with silver. Hall measurement confirms that the deposited PbI2 films are p-type and the electrical resistivity of the film increases from 1.1 × 104 to 1.8 × 107 Ω cm as doping concentration increases from 1 to 5%.