Temperature dependent raman and photoluminescence of an individual Sn-doped CdS branched nanostructure

Abstract

Temperature dependent Raman spectra and photoluminescence, as well the Raman mapping of different parts in an individual Sn-doped CdS comb-like nanostructure reveal that the stronger electron-phonon coupling exist at the trunk-branch junctions than other parts. The Huang-Rhys factor was calculated and further confirms that the strong electron-phonon correlation at the junction. The localized deformation from the Sn dopant in the lattice leads to strong electron-phonon coupling at the local junction, which is proved by the scanning transmission electron microscope and energy dispersion spectrum. Moreover, the lifetime of near-band-edge emission and deep-level emission drastically increase with decreasing temperature, which both relate to the localized electron-phonon coupling and relaxation process. This work provides a clear description of the localized carrier correlation in the cross junction part of these branched nanostructures, which can be used to modulate the optoelectronic performance of micro/nanodevices.