Kim Hwi-Jae, Jo Jung-Ho, Yoon Suk-Young, Jo Dae-Yeon, Kim Hyun-Sik, Park Byoungnam, Yang Heesun
Department of Materials Science and Engineering, Hongik University, Seoul 04066, Korea.
Materials (Basel). 2019 Jul 15;12(14):2267. doi: 10.3390/ma12142267.
The doping of transition metal ions, such as Cu and Mn into a quantum dot (QD) host is one of the useful strategies in tuning its photoluminescence (PL). This study reports on a two-step synthesis of Cu-doped InP QDs double-shelled with ZnSe inner shell/ZnS outer shell. As a consequence of the double shelling-associated effective surface passivation along with optimal doping concentrations, Cu-doped InP/ZnSe/ZnS (InP:Cu/ZnSe/ZnS) QDs yield single Cu dopant-related emissions with high PL quantum yields of 57-58%. This study further attempted to tune PL of Cu-doped QDs through the variation of InP core size, which was implemented by adopting different types of Zn halide used in core synthesis. As the first application of doped InP QDs as electroluminescent (EL) emitters, two representative InP:Cu/ZnSe/ZnS QDs with different Cu concentrations were then employed as active emitting layers of all-solution-processed, multilayered QD-light-emitting diodes (QLEDs) with the state-of-the-art hybrid combination of organic hole transport layer plus inorganic electron transport layers. The EL performances, such as luminance and efficiencies of the resulting QLEDs with different Cu doping concentrations, were compared and discussed.
将过渡金属离子（如铜和锰）掺杂到量子点（QD）主体中是调节其光致发光（PL）的有效策略之一。本研究报道了一种两步合成法制备的铜掺杂InP量子点，其具有ZnSe内壳/ZnS外壳的双层结构。由于双层结构相关的有效表面钝化以及最佳掺杂浓度，铜掺杂的InP/ZnSe/ZnS（InP:Cu/ZnSe/ZnS）量子点产生了与单个铜掺杂剂相关的发射，光致发光量子产率高达57-58%。本研究进一步尝试通过改变InP核尺寸来调节铜掺杂量子点的光致发光，这是通过在核合成中采用不同类型的卤化锌来实现的。作为掺杂InP量子点作为电致发光（EL）发射体的首次应用，两种具有不同铜浓度的代表性InP:Cu/ZnSe/ZnS量子点随后被用作全溶液处理的多层量子点发光二极管（QLED）的有源发光层，该QLED采用了有机空穴传输层加无机电子传输层的先进混合组合。对所得具有不同铜掺杂浓度的QLED的电致发光性能，如亮度和效率进行了比较和讨论。
