Authors: Prashant K Sarswat Michael L Free
Publish Date: 2014/11/20
Volume: 50, Issue: 4, Pages: 1613-1623
Abstract
Impurities in Cu2ZnSnS4 CZTS can alter the electronic and optical properties which may reduce photovoltaic device efficiency Phonon dispersion susceptibility can be used to investigate the effects of foreign dopants on pairing between atoms within lattice In order to investigate the effect of free holes on the optical phonons and asymmetry in the Raman peaks due to impurities Sb Fe and Agdoped CZTS thin films were prepared and systematically studied Doping with impurities causes a shift in Raman peak frequency as well as linewidth An investigation has been made based on the reduced mass of the vibrating CZTS lattice that changes due to dopant addition For polycrystalline Sbdoped CZTS the predicted wavenumber shift for Raman ‘A’ mode follows a similar trend as evidenced in experiments and can be explained by the squareroot relationship between frequency and the vibrating mass Raman lineshape for Sbdoped CZTS thin films and nanocrystals becomes wider asymmetric and moves toward lower vibrational frequency when laser power density increases Atomic force microscopy was also performed to examine surface properties
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