Se/S Ratio-Dependent Properties and Application of Gradient-Alloyed CdSe1–xSx Quantum Dots: Shell-free Structure, Non-blinking Photoluminescence with Single-Exponential Decay, and Efficient QLEDs
Se/S Ratio-Dependent Properties and Application of Gradient-Alloyed CdSe1–xSx Quantum Dots: Shell-free Structure, Non-blinking Photoluminescence with Single-Exponential Decay, and Efficient QLEDs
复制标题
梯度合金 CdSe1−xSx 量子点的 Se/S 比相关特性及应用：无壳结构、单指数衰减的非闪烁光致发光和高效 QLED
DOI：
10.1021/acsami.8b17127
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发表时间：
2019
影响因子：
9.5
通讯作者：
Lin Song Li
中科院分区：
文献类型：
--
作者：
Huimin Zhang;Fangfang Wang;Yanmin Kuang;Zhaohan Li;Qingli Lin;Huaibin Shen;Hongzhe Wang;Lijun Guo;Lin Song Li
胶体量子点（QDs）是一种具有广泛应用前景的光学和光电子材料。激发态性质是评价量子点质量的重要指标，直接影响到量子点的应用。与通过控制表面工程（表面配体、壳层厚度等）来调节激发态性质不同，本文采用二苯基膦作为有益添加剂，在低温（~ 180℃）下，通过调整组成来合成具有控制激发态性质的高质量无壳合金CdSe1-xSx（简称CdSeS）量子点。优化后的CdSeS无壳合金量子点（Se/S = 1:8）在激发态可调的情况下表现出优异的光学性能，包括单指数光致发光（PL）衰减动力学，半峰宽度窄至28 nm，无闪烁发射行为（>98%“打开”时间）。此外，利用传统器件结构制备了全溶液处理的多层量子点发光二极管，以评估具有成分控制激发态的量子点的性能。该器件的最大亮度为92,330 cd m-2，电流效率为50.3 cd a - 1，外量子效率为14.5%。
Colloidal quantum dots (QDs) are promising optical and optoelectronic materials for various applications. The excited state properties are important indexes to assess the quality of QDs and may directly affect their applications. Different from controlling surface engineering (surface ligands, shell thickness, etc.) to adjust excited state properties, high-quality shell-free alloyed CdSe1–xSx(simplified as CdSeS) QDs with controlled excited state properties were synthesized by tuning the composition and using diphenylphosphine as a beneficial additive at a low temperature (∼180 °C). The optimized CdSeS shell-free alloyed QDs (Se/S = 1:8) exhibited excellent optical properties with tuning of the excited state, including single-exponential photoluminescence (PL) decay dynamics, a narrow full width at half maximum of 28 nm, and non-blinking emission behavior (>98% “on” time). Furthermore, all-solution-processed, multilayered quantum dot light-emitting diodes were fabricated using the conventional device structure to assess the performance of QDs with composition-controlled excited states. The best device displayed a maximum luminance of 92,330 cd m–2, a current efficiency of 50.3 cd A–1, and an external quantum efficiency of 14.5%.