Correlation of photoluminescence quenching with Charge Transport in group III (Al, Ga & In) elements doped CdS/PVA NCs: Experimental and First Principles Studies

Nanocomposites of polyvinyl alcohol (PVA) with group III elements doped CdS have been synthesized via in situ chemical route. The optical properties of doped and pristine products are investigated by Raman spectroscopy, optical transmittance and photoluminescence (PL). Raman spectroscopy has shown peaks at 300 cm(-1), 603 cm(-1) and 900 cm(-1) corresponding to first, second and third order scattering of longitudinal optical (LO) phonon modes respectively. Electron-phonon interactions are estimated from Raman spectra and found to be stronger in doped samples. All the samples show high transmittance in wavelength region above 500 nm. In the present work, PL quenching has been observed in Al, Ga and In doped CdS/PVA. Density functional theory (OFT) has been employed to interpret the relation between reduction in PL intensity and charge on nanoclusters. DFT simulations indicate that decrease of charge on S results in corresponding quenching of PL (C) 2014 Elsevier B.V. All rights reserved.