Effect of selenium layer thickness on structural and optical properties of nanocrytalline PbSe multilayer thin films

摘要

Lead selenide multilayer thin films were prepared by thermal evaporation technique by successive coatings of Lead and Selenium layers. The layer thickness of Se varies from10 to 40 nm whereas 10 nm layer thickness of Pb maintained at the cases. The polycrystalline nature with cubic structure of all as deposited films observed from X-Ray diffractogram. The lattice constant of 1.53 Aï??° observed in all the films. The absorption shift toward shorter wavelength shows the presence of nanoparticle trapped at the interfaces of Lead and Selenium. The rise in transmittance spectra around 1585 nm indicates the nanocrystalline effect of the prepared films. To confirm the quantum confinement effect of as deposited films the Brus and quantum mechanical modal calculation were done from energy shift and are well agreed with each other and the calculated particle size varies from 1.2 to 2 nm.