Kang Byoung-Ho, Kim Ju-Seong, Lee Jae-Sung, Lee Sang-Won, Sai-Anand Gopalan, Jeong Hyun-Min, Lee Seung-Ha, Kwon Dae-Hyuk, Kang Shin-Won
J Nanosci Nanotechnol. 2015 Sep;15(9):7416-20. doi: 10.1166/jnn.2015.10542.
In this paper, we propose interface engineering between cadmium selenide/zinc sulfide (CdSe/ZnS) quantum dots (QDs) as the emissive layer (EML) and ZnO nanocrystals (NCs) as the electron transport layer (ETL) for reducing the potential barrier in QDs based light-emitting diode (QLED). The n-type ZnO NCs were effective in confining charge to the QDs EML because of their wide band gap. The ZnO NCs were synthesized using a modified sol-gel process and were applied as the ETL in QLED. For comparison, a standard QLED with Tris(8-hydroxyquinolinato)aluminium as the ETL was also fabricated. The standard QLED was shown to have a luminance of 11,240 cd/m2 and current efficiency of 2.3 cd/A. However, QLED with ZnO NCs showed a higher luminance of 28,760 cd/m2 and current efficiency of 4.9 cd/A than the reference structure, and so has more efficient charge transport. Thus, QLED with ZnO NCs not only simplified the process, but also enhanced the luminance and current efficiency by factor of two.
在本文中，我们提出在作为发光层（EML）的硒化镉/硫化锌（CdSe/ZnS）量子点（QDs）与作为电子传输层（ETL）的氧化锌纳米晶体（NCs）之间进行界面工程，以降低基于量子点的发光二极管（QLED）中的势垒。由于其宽带隙，n型ZnO纳米晶体在将电荷限制在量子点发光层方面是有效的。ZnO纳米晶体采用改进的溶胶-凝胶工艺合成，并应用于QLED中的电子传输层。为了进行比较，还制备了以三（8-羟基喹啉）铝作为电子传输层的标准QLED。标准QLED的亮度为11240 cd/m²，电流效率为2.3 cd/A。然而，与参考结构相比，采用ZnO纳米晶体的QLED显示出更高的亮度，为28760 cd/m²，电流效率为4.9 cd/A，因此具有更高效的电荷传输。因此，采用ZnO纳米晶体的QLED不仅简化了工艺，而且将亮度和电流效率提高了两倍。
