Quantum Confinement and Crystalline Structure of CdSe Nanocrystalline Films

Nanocrystalline CdSe films were grown onto glass substrates by the chemical bath method. Different constant deposition temperatures (Td) were employed in the range 4–65 °C. Average grain size (GS) increased monotonically with Td, reaching saturation at ∼65 °C. The GS values were in the interval 5–16 nm. At low Td values (4–15 °C), the structural phase was hexagonal wurtzite (W), for intermediate values, a wurtzite and zincblende (ZB) mixture of phases was found, and at high Td (65 °C) only cubic ZB phase was present in the layers. The variation of the bandgap as a result of the structural phase change and quantum confinement is studied.