High-efficiency quantum-dot light-emitting devices with enhanced charge injection
High-efficiency quantum-dot light-emitting devices with enhanced charge injection
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DOI：
10.1038/nphoton.2013.70
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发表时间：
2013-05-01
期刊：
影响因子：
35
通讯作者：
Kazlas, Peter T.
中科院分区：
文献类型：
--
作者：
Mashford, Benjamin S.;Stevenson, Matthew;Kazlas, Peter T.
我们报道了一种颜色饱和，红色量子点发光器件（QLED）使用倒置的有机-无机杂化器件结构和胶体CdSe-CdS（核-壳）量子点发射器。量子点与相邻的ZnO纳米晶体层（其形成电子传输层）的强电子耦合促进电荷转移，这负责注入电子和维持量子点发射体的最佳电荷平衡。我们发现，QLED的性能可以通过控制量子点薄膜内的电致发光复合区从量子点-ZnO界面的距离来修改。据报道，器件的发光效率为19 cd A（-1），对应于18%的外量子效率（接近理论最大值20%）和90%的内量子效率。相应的发光功率效率超过25 lm W-1，由于该设备的低工作电压。
We report a colour-saturated, red quantum-dot light-emitting device (QLED) using an inverted organic-inorganic hybrid device structure and colloidal CdSe-CdS (core-shell) quantum-dot emitters. The strong electronic coupling of quantum dots to an adjacent layer of ZnO nanocrystals (which form the electron transport layer) facilitates charge transfer, which is responsible for both injecting electrons and maintaining an optimal charge balance for the quantum dot emitters. We show that QLED performance can be modified by controlling the distance of the electroluminescence recombination zone within the quantum dot film from the quantum dot-ZnO interface. Devices are reported with a luminous efficiency of 19 cd A(-1), corresponding to an external quantum efficiency of 18% (which is close to the theoretical maximum of 20%) and an internal quantum efficiency of 90%. The corresponding luminous power efficiency exceeds 25 lm W-1 due to the low operating voltage of the device.