Luminescence Studies of II-VI Nanocrystals
(CdSe/PVA & ZnSe/PVA)
Kamal K. Kushwah1, Pranav Singh2 and M.Ramrakhiani2
1 Department of Applied Physics, Jabalpur Engineering College, Jabalpur, M.P., India.
2Department of Post Graduate Studies and Research in Physics and Electronics,
Rani Durgavati Vishwavidhyalaya, Jabalpur, M.P., India
Photoluminescence, Polymer Nanocomposite and Nanocrystals.
The nanocomposite films of CdSe and ZnSe nanocrystals in polyvinyl alcohol (PVA) matrix were synthesized by environmental friendly chemical method. These composites were characterized by X-ray diffraction which indicates the nanocrystalline structure of CdSe and ZnSe in polymer matrix with particle size up to a few nm. The Particle size is found to decrease by increasing PVA Concentration and metal selenide (ZnSe/CdSe) content. The photoluminescence properties of these composite films with varying concentration of PVA and metal selenide (ZnSe/CdSe) content have been investigated.
The PL peak of CdSe and ZnSe were observed at 510 nm and 465 nm respectively. The higher intensity is observed by increasing PVA content in CdSe and ZnSe nanocomposite films without any change in position of PL peak. It is also revealed that, In ZnSe & CdSe/PVA nanocomposites with varying ZnSe/CdSe content, PL peak shifts towards shorter wavelength as particle size is reduced.
This PL emission may be attributed due to various surface states available and the Blue shift could be attributed to size reduction of PVA matrix to CdSe nanoparticles with variations of CdSe content. Due to proper passivation of surface states non-radiative transition are reduced which enhance the PL intensity. The polymer matrix acts to stabilize the nanoparticles. Due to the PL peak in green and blue region these composite films are promising materials for optical display devices.
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