Fabrication of CuInTe2 and CuInTe(2-x)Se(x) ternary gradient quantum dots and their application to solar cells

We report the first synthesis of colloidal CuInTe2, CuInTe2-xSex gradient alloyed quantum dots (QDs) through a simple hot injection method. We confirmed the composition of synthesized QDs to cationic rich phase of CuIn1.5Te2.5 and Cu0.23In0.36Te0.19Se0.22 with XPS and ICP analysis, and we have also found that the gradient alloyed Cu0.23In0.36Te0.19Se0.22 QDs exhibit greatly improved stability over the CuIn1.5Te2.5 QDs. The solution-processed solar cell based on the gradient alloyed Cu0.23In0.36Te0.19Se0.22 QDs exhibited 17.4 mA/cm(2) of short circuit current density (Jsc), 0.40 V of open circuit voltage (Voc), 44.1% of fill factor (FF), and 3.1% of overall power conversion efficiency at 100 mW/cm(2) AM 1.5G illumination.