量子点
光致发光
量子产额
材料科学
磷化铟
光电子学
三元运算
电致发光
铟
蓝移
磷化物
纳米技术
图层(电子)
金属
荧光
光学
砷化镓
冶金
物理
程序设计语言
计算机科学
作者
Kyung-Hye Kim,Jaemin Jo,Dae‐Yeon Jo,Chang-Yeol Han,Suk‐Young Yoon,Yuri Kim,Yang‐Hee Kim,Yun-Hyuk Ko,Sung Woon Kim,Changhee Lee,Heesun Yang
标识
DOI:10.1021/acs.chemmater.0c00551
摘要
In contrast to a substantial progress of heavy metal-free green and red emitters exclusively from indium phosphide (InP) quantum dots (QDs), the development of non-Cd blue QDs remains nearly unexplored. The synthesis of blue InP QDs with a bright, deep-blue emissivity is not likely viable, which is primarily associated with their intrinsic size limitation. To surmount this challenge, herein, the first synthesis of blue-emissive ternary InGaP QDs through In3+-to-Ga3+ cation-exchange strategy is implemented. Pregrown InP QDs turn out to be efficiently Ga-alloyed at a relatively low temperature of 280 °C in the presence of Ga iodide (GaI3), and the degree of Ga alloying is also found to be systematically adjustable by varying GaI3 amounts. Such cation-exchanged InGaP cores are surface-passivated sequentially with ZnSeS inner and ZnS outer shells. As the amount of GaI3 added for cation exchange increases, the resulting double-shelled InGaP/ZnSeS/ZnS QDs produce consistent blue shifts in photoluminescence (PL) from 475 to 465 nm, while maintaining high PL quantum yield in the range of 80–82%. Among a series of QD samples, above 465 nm emitting InGaP/ZnSeS/ZnS QDs are further employed as an emitting layer of an all-solution-processed electroluminescent device. This unprecedented InGaP QD-based blue device generates maximum values of 1038 cd/m2 in luminance and 2.5% in external quantum efficiency.
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