Nanocrystal Size-Dependent Efficiency of Quantum Dot Sensitized Solar Cells in the Strongly Coupled CdSe Nanocrystals/TiO2 System

• DOI: 10.1021/acsami.6b05552
• Publication Date: 2016-05-25T21:06:10Z
• Authors: Hyeong Jin Yun; Taejong Paik; Benjamin Diroll; Michael E. Edley; Jason B. Baxter; Christopher B. Mu...
• Keywords: Absorbance; Multiple exciton generation; Cadmium selenide; Quantum Efficiency; Dispersity

Light absorption and electron injection are important criteria determining solar energy conversion efficiency. In this research, monodisperse CdSe quantum dots (QDs) synthesized with five different diameters, the size-dependent efficiency of dot sensitized cell (QDSSCs) is investigated by employing atomic inorganic ligand, S(2-). Absorbance measurements transmission microscopy show that diameters uniform QDs 2.5, 3.2, 4.2, 6.4, 7.8 nm. Larger generate a larger amount charge under irradiation long wavelength photons, as verified absorbance results external efficiencies. However, smaller exhibit faster kinetics from to TiO2 because high level CBCdSe, time-resolved photoluminescence internal results. Importantly, S(2-) ligand significantly enhances electronic coupling between TiO2, yielding an enhancement transfer rate at interfacial region. As result, helps improve new efficiency, showing best performance 4.2-nm QDs, whereas conventional mercaptopropionic acid, does not any differences in according size QDs. The findings reported herein suggest reinforces influence confinement on QDSSCs.