Lee Kwangkeun, Park Ganghyun, Chun Beomsoo, Yoo Taewoong, Shin Doyoon, Bae Wan Ki, Lee Taesoo, Kwak Jeonghun
Department of Electrical and Computer Engineering, Inter-university Semiconductor Research Center, and SOFT Foundry Institute, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
SKKU Advanced Institute of Nano Technology (SAINT), Sungkyunkwan University, Seobu-ro, Jangan-gu, Suwon-si, 16419 Gyeonggi-do, Republic of Korea.
ACS Appl Mater Interfaces. 2025 Jan 8;17(1):1451-1459. doi: 10.1021/acsami.4c13991. Epub 2024 Dec 23.
Quantum-dot (QD) light-emitting diodes (QLEDs) are garnering significant attention owing to their superb optoelectrical properties, but the overinjection of electrons compared to holes into the emissive layer (EML) is still a critical obstacle to be resolved. Current approaches, such as inserting a charge-balancing interlayer and mixing p-type organic additives into the EML, face issues of process complexity and poor miscibility. In this work, we demonstrate efficient InP QLEDs by simply embedding NiO nanoparticles (NPs) into the EML which forms a homogeneous QD-metal oxide hybrid EML. Precisely changing the NiO NPs concentration enables an effective modulation of the valence state of the hybrid EML, while controlling the exciton quenching phenomena stemming from the metal oxide additives. Moreover, the inorganic hybrid EML exhibits superior electrical stability compared to that of typical organic additives. In detail, it possesses an upshifted valence state by approximately 0.2 eV, leading the QLEDs to a 3.7-fold increase in luminance, 1.7-fold improvement in external quantum efficiency, and 3-fold extension in operational half-lifetime, simultaneously. Comprehensive analyses on the optoelectrical and morphological characteristics confirm that the hybrid EML is suitable for realizing efficient and stable InP QLEDs via a simple fabrication method. Therefore, we expect that this approach would provide valuable insights into the development of high-performance and low-cost QLEDs.
量子点（QD）发光二极管（QLED）因其卓越的光电性能而备受关注，但与空穴相比，电子向发光层（EML）的过度注入仍是一个亟待解决的关键障碍。目前的方法，如插入电荷平衡中间层和将p型有机添加剂混入EML中，面临着工艺复杂和混溶性差的问题。在这项工作中，我们通过简单地将NiO纳米颗粒（NPs）嵌入EML中来展示高效的InP QLED，这形成了一种均匀的量子点-金属氧化物混合EML。精确改变NiO NPs的浓度能够有效调节混合EML的价态，同时控制源自金属氧化物添加剂的激子猝灭现象。此外，与典型的有机添加剂相比，无机混合EML表现出优异的电稳定性。具体而言，它的价态上移了约0.2 eV，使得QLED的亮度提高了3.7倍，外量子效率提高了1.7倍，工作半衰期延长了3倍。对光电和形态特征的综合分析证实，混合EML适用于通过简单的制造方法实现高效且稳定的InP QLED。因此，我们期望这种方法能为高性能和低成本QLED的发展提供有价值的见解。
