Park Myeongjin, Song Jiyun, An Myungchan, Lim Jaehoon, Lee Changhee, Roh Jeongkyun, Lee Donggu
Department of Electrical and Computer Engineering, Inter-university Semiconductor Research Center, Seoul National University Seoul 08826 Republic of Korea.
Realistic Media Research Center, Innovative Technology Research Division, Gumi Electronics & Information Technology Research Institute (GERI) Gumi 39253 Republic of Korea
RSC Adv. 2020 Feb 26;10(14):8261-8265. doi: 10.1039/d0ra00653j. eCollection 2020 Feb 24.
Colloidal quantum-dot-based light-emitting diodes (QD-LEDs) have gained tremendous attention as great candidates to potentially replace current emissive display technologies. The luminescence efficiency of a QD LED has increased rapidly in the past decade; this was triggered by the use of metal oxides in the charge transport layers, particularly zinc oxide (ZnO) for the electron transport layer (ETL). However, the ZnO ETL often results in undesirable device performance such as efficiency roll-off and poor device stability because of excessive electron injection into the QD emissive layer. Here, we explore solution-processable tin dioxide (SnO) nanoparticles (NPs) as alternatives to ZnO NPs for the ETL in QD-LEDs. We evaluated the thin-film quality and electrical performance of SnO NPs and then applied them to the ETL for constructing QD-LEDs. As a result of the smooth surface morphology, moderate electron-transport ability, and lower carrier concentration compared to ZnO NPs, the QD-LED with SnO NP-ETL exhibited improved performance in terms of lower turn-on and operating voltages, maximum luminance, improved efficiency roll-off, and improved power efficiency over the reference device with the ZnO NP-ETL. This shows promising potential for SnO NPs in optoelectronic applications.
基于胶体量子点的发光二极管（QD-LED）作为有可能取代当前发光显示技术的优秀候选者，已引起了极大关注。在过去十年中，QD-LED的发光效率迅速提高；这是由电荷传输层中使用金属氧化物引发的，特别是用于电子传输层（ETL）的氧化锌（ZnO）。然而，由于过多的电子注入到QD发光层中，ZnO ETL常常导致不理想的器件性能，如效率滚降和较差的器件稳定性。在此，我们探索可溶液加工的二氧化锡（SnO）纳米颗粒（NP）作为QD-LED中ETL的ZnO NP的替代品。我们评估了SnO NP的薄膜质量和电学性能，然后将它们应用于ETL以构建QD-LED。由于与ZnO NP相比具有光滑的表面形态、适度的电子传输能力和更低的载流子浓度，具有SnO NP-ETL的QD-LED在开启和工作电压更低、最大亮度、改善的效率滚降以及功率效率方面表现出比具有ZnO NP-ETL的参考器件更好的性能。这表明SnO NP在光电子应用中具有广阔的潜力。
