Raman and photoluminescence investigation of CdS/CdSe quantum dots on TiO2 nanoparticles with multi-walled carbon nanotubes and their application in solar cells

Raman spectroscopy and photoluminescence (PL) were used to investigate the improved short-circuit current density (J(SC)) of CdS/CdSe quantum dot (QD)-sensitized solar cells with multi-walled carbon nanotubes (MWCNTs). Raman and PL experiments were carried out in order to explore the hot-electron and cold-electron injections, respectively. The experimental results showed that the concentration of MWCNTs influences the hot-electron and cold-electron injections from CdS/CdSe QDs to TiO2 nanoparticles. Therefore, the improved J(SC) in CdS/CdSe QD-sensitized solar cells can be explained as due to the better electron injections. (C) 2015 Elsevier B.V. All rights reserved.