Growth and Characterizes of PbI2 Films By Vacuum Evaporation Method

In this work, thin films of lead iodide (PbI2) were deposited on glass substrates with different thicknesses by vacuum thermal evaporation method. The structural, chemical, electrical and optical characteristics of the thin films were studied. XRD analysis showed that lead iodide film is polycrystalline having hexagonal structure. A particle size was estimated by Williamson - Hall technique (13) nm and strain (4.90*10-3) are founded from the intercept with y-axis and slope for PbI2. The UV-VIS measurements illustrated that the lead iodide has a direct optical band gap and Urbach energy to be 0.677 eV2. Raman peaks are detected at 70, 96, 99.5, 188 and 202 cm-1 which corresponding to characteristic of PbI2 at (E21, A11, 2E11 and A1g). The FTIR spectrum of PbI2 thin film showed six bands at 1650, 1900, 3100, 3400, 3600 and 3800 cm-1. Mechanism of dc transport was also analyzed in the temperature range 315–395 K. Also the variation of reflectivity in the range near infrared is conductive generally attributed to thin film nature, where this film contain light scattering and large surface area, which enhance the optical absorption and hence, a low reflectivity is obtained.