Photovoltaic Properties of Colloidal ZnTe/ZnSe (core/shell) Type II Quantum Dots

  • Sungjee Kim, Department of Chemistry, Department of Chemical Engineering, Pohang University of Science and Technology, Korea
  • Jiwon Bang, Department of Chemistry, Department of Chemical Engineering, Pohang University of Science and Technology, Korea
  • Ji-Hwang Lee, Department of Chemistry, Department of Chemical Engineering, Pohang University of Science and Technology, Korea
  • Juwon Park, Department of Chemistry, Department of Chemical Engineering, Pohang University of Science and Technology, Korea
  • Jutack, Department of Chemistry, Department of Chemical Engineering, Pohang University of Science and Technology, Korea
  • Kilwon Cho, Department of Chemistry, Department of Chemical Engineering, Pohang University of Science and Technology, Korea

    • Colloidal II- ? semiconductor quantum dots (QDs) are prepared and exploited for photovoltaic devices. To further optimize the efficiency of solar cells by using different type of QDs, we investigate type-II core/shell QDs. Type-II QDs can have small effective band gaps than those of the constituent materials and can have potentials to effectively transfer the photoinduced carriers by the unique band offset characteristics. Therefore, type-II QDs can be advantageous for photovoltaic devices because of their broad absorptions and capable photoinduced charge separation. We synthesize colloidal ZnTe/ZnSe (core/shell) type-II QDs and their absorption spectra covered from UV to 600 nm. These type-II QDs are made of relatively less toxic elements when compared to conventional QDs such as CdSe QDs, and can be potentially more viable for commercialization. We made ZnTe/ZnSe (core/shell) QDs - P3HT hybrid solar cell device, and characterize their photovoltaic properties. ZnTe/ZnSe (core/shell) QDs - P3HT hybrid solar cell has more efficient light harvesting and increase power conversion efficiency compared with P3HT solar cell.