title: Phosphine-free synthesis of CdSe quantum dots in a new co-capping ligand system.
abstract: High-quality CdSe quantum dots with zinc blende structure were successfully synthesized via a new cheaper, greener phosphine-free route, using environmentally friendly N,N-dimethyl-oleoyl amide as the solvent of Se. The process eliminates trioctylphoshine from the synthesis, using oleic acid (OA) as a primary capping ligand and benzophenone (BP) as a secondary ligand in the noncoordinating solvent. It has been found that the addition of BP can improve the size distribution (below 10%) of as-synthesized CdSe quantum dots greatly, and the nucleation and growth process can also be well-separated. Moreover, a comprehensive examination on the control of particle size and size distribution was performed by systematically varying the BP/OA molar ratio. The phosphine-free route enables us to obtain high-quality CdSe quantum dots with sharp UV-vis absorption peak, size ranging from 2.8 to 6.8 nm, and narrow full width of half-maximum between 27 and 35 nm with purely band-edge luminescence, and without any post-synthesis processing.
authors.affiliation: School of Materials Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009, PR China.
authors.forename: Chun
authors.initials: C
authors.lastname: Wang
authors.forename: Yang
authors.initials: Y
authors.lastname: Jiang
authors.forename: Zhongping
authors.initials: Z
authors.lastname: Zhang
authors.forename: Guohua
authors.initials: G
authors.lastname: Li
authors.forename: Lanlan
authors.initials: L
authors.lastname: Chen
authors.forename: Jiansheng
authors.initials: J
authors.lastname: Jie