Jesús Manuel Rivas

This article describes the synthesis of Cd $_{x}$ Zn $_{1-}$ $_{x}$ S quantum dots prepared using the successive ionic layer adsorption and reaction method and incorporated into a photovoltaic device. The Cd $_{x}$ Zn $_{1-}$ $_{x}$ S quantum dots exhibit good optical and electrical properties. The photovoltaic device has the configuration TiO $_{2}$ /Cd $_{0.75}$ Zn $_{0.25}$ S $_{1}$ /ZnS. A photoconversion efficiency of 3.6% was obtained with this device. This efficiency corresponds to a 16% relative increment compared with a reference sample with the configuration TiO $_{2}$ /Cd $_{1}$ Zn $_{0}$ S $_{1}$ /ZnS. The improvement is associated with an increment in the open-circuit voltage (V $_{oc}$ ) from 0.517 to 0.725 V. The corresponding short-circuit current density (J $_{sc}$ ) was reduced from 12.15 to 11.66 mA cm−2. Electrochemical impedance spectroscopy analyses confirm that the behavior of the device was due to a recombination rate reduction obtained as a result of surface passivation between the TiO $_{2}$ layer and the Cd $_{x}$ Zn $_{x-1}$ S QDs interface.