Formation of CdSe/CdTe quantum dots in Multilayer Thin films using PVD Method

Nanocrystals of CdSe have been produced in CdTe hetrostructure layer by thermal evaporation method. Structural studies were done by X-ray diffractometer. Quantum confinement effect of CdSe/CdTe nanocrystals was analysed from optical studies. Bulk CdSe has a bandgap energy of 1.756eV that can be shifted to larger values by reducing the crystal size to dimensions smaller than the Bohr radius of the exciton. Experimentally measured band gap shifts with respect to the bulk value for quantum dot thin films are compared with the predictions of the effective mass approximation model (i.e., Brus model) and Quantum mechanical model. Size of the crystallites calculated from both the models was found to agree with each other.