团聚效应对基于CdSe/ZnS量子点的电致发光二极管性能的影响

通过旋涂含有CdSe/ZnS量子点(Quantum dot,QD)的溶液为发光层薄膜,制备了叠层结构的电致发光二极管,利用原子力显微镜研究了QD发光亮度、薄膜形貌与其工艺条件、参数的关系。研究结果表明:随QD厚度的增加,QD纳米粒子薄膜由单层向多层薄膜形成,QD纳米颗粒发生团聚现象,并使器件亮度降低。此外,退火温度对QD薄膜形貌及其发光强度影响很大:当退火温度高于150 ℃时,产生的热量也会造成QD纳米粒子团聚,并导致QLED器件发光性能下降。

Influence of Agglomeration in CdSe/ZnS Quantum Dot on The Performances of Light-emitting Diode

Light-emitting diodes containing multilayer laminated structure are fabricated by spin-coating CdSe/ZnS quantum dots (QD) films as emitting layer. The dependences of process conditions and parameters on the electroluminescence and the QD film morphology are researched by using atomic force microscopy. The results show that with the increased thickness of QD, the multi-layer nano-particle films are formed, which leads to the QD nano-particles agglomerate and the brightness of device decrease. In addition, the annealing temperature of the QD layer has an important impact on the device brightness. When annealing temperature is low, the device shows poor performance due to the solvent volatized incompletely. When annealing temperature is above 150 ℃, the heat generated from annealing will cause the agglomeration of the QD nano-particles and then the performances of devices decline.