Solvothermal synthesis, deposition and characterization of cadmium selenide (CdSe) thin films by thermal evaporation technique

Nanocrystalline compound semiconductor Cadmium Selenide was synthesized by the solvothermal method using Cd(NO3)2.4H2O and Se metal granules. The synthesized nanocrystalline CdSe particles were subjected to vacuum annealing at 450 °C to maintain the hexagonal phase. The as synthesized and annealed powders were analyzed using XRD, SEM, EDX and DTA. The X-ray diffraction pattern of the as synthesized powder shows cubic phase, whereas the 450 °C annealed CdSe powder exhibits hexagonal phase. The annealed nanocrystalline CdSe was pelletized using hydraulic pressure of 5 ton and used to deposit thin films at different substrate temperature like Room Temperature (RT), 150, 250, 350 and 450 °C by thermal evaporation using glass as substrate. The deposited films were subjected to XRD, SEM, EDX, UV–vis, Photoluminescence, Raman Spectroscopy and Hall Effect measurement to study their properties. The thickness of the films was measured with thickness profilometer. The thermally deposited CdSe films exhibit the hexagonal structure with n-type conductivity.

► Synthesized nanocrystalline CdSe annealed at 450 °C exhibits hexagonal phase.
► The 450 °C annealed CdSe deposited film by the thermal evaporation possess hexagonal phase.
► The thickness of the film was measured, which gets varied from 60–85 nm.
► SEM shows the smooth surface, agglomerated particles and the composition is 1:1.
► The thermally deposited CdSe films exhibit n-type conductivity.