Synthesis of Alloyed CdxZn1-xS Quantum Dots for Photovoltaic Applications

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.