A strategy to boost the cell performance of CdSexTe1-x quantum dot sensitized solar cells over 8% by introducing Mn modified CdSe coating layer

CdSexTe1-x alloyed colloidal quantum dots show great potential application on quantum dot-sensitized solar cells (QDSCs) due to its relatively wide light absorption range and high chemical stability. In this respect, a thin Mn modified CdSe layer is introduced into TiO2/CdSexTe1-x alloyed QDs surface via a simple chemical bath deposition method (CBD) in order to further improve the cell performance. The power conversion efficiency of CdSexTe1-x QDSCs has been improved to 8.14%. Detailed investigation on the influence of this modification toward the TiO2/CdSexTe1-x interface on the cell performance reveals that introduction of Mn into CdSe QDs is found to facilitate the Mn-doped CdSe deposition and improve the light absorption of the device. In the meantime, the existence of the (Mn-)CdSe layer can also work as a passivation layer to reduce charge recombination. (C) 2015 Elsevier B.V. All rights reserved.