Shin Yun Seop, Yoon Yung Jin, Lee Kang Taek, Lee Woojin, Kim Hyeon Seo, Kim Jae Won, Jang Hyungsu, Kim Minjin, Kim Dong Suk, Kim Gi-Hwan, Kim Jin Young
Perovtronics Research Center, Department of Energy Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, South Korea.
Ulsan Advanced Energy Technology R&D Center, Korea Institute of Energy Research, 25 Techno saneop-ro 55beon-gil, Nam-gu, Ulsan 44776, Republic of Korea.
ACS Appl Mater Interfaces. 2020 Jul 15;12(28):31582-31590. doi: 10.1021/acsami.0c06213. Epub 2020 Jul 6.
Inorganic lead halide perovskite nanocrystals (PeNCs) have intensively drawn attention as efficient light-emitting materials for optoelectronic applications due to their fine optoelectronic properties with a high photoluminescence quantum yield and easily tunable saturated emission color. However, the poor stability of the red-emitting PeNCs has become an obstacle because of the uncontrollable iodine substitution from the PeNCs due to weak Pb-I bonding. In this work, we have demonstrated a ligand-mediated post-treatment (LMPT) method using a halide ion-pair ligand, tridodecylmethyl ammonium iodide (TrDAI), for the air stable and high-quality red-emitting PeNCs. Through the LMPT method, the optoelectronic properties of red-emitting PeNCs are dramatically improved resulting in a PLQY of 88.7% at 637 ± 2 nm emission with an increased carrier lifetime from 20.77 to 31.52 ns. We achieve highly efficient red perovskite light-emitting diodes exhibiting a maximum current efficiency of 7.69 cd A and an external quantum efficiency of 6.36% at 637 ± 2 nm electroluminescence emission with a sharp full-width at half maximum of 31 nm.
无机铅卤化物钙钛矿纳米晶体（PeNCs）因其具有高光致发光量子产率和易于调节的饱和发射颜色等优良光电特性，作为用于光电子应用的高效发光材料受到了广泛关注。然而，由于Pb-I键较弱导致PeNCs中碘的不可控取代，红色发射PeNCs的稳定性较差已成为一个障碍。在这项工作中，我们展示了一种使用卤化物离子对配体三（十二烷基）甲基碘化铵（TrDAI）的配体介导后处理（LMPT）方法，用于制备空气稳定且高质量的红色发射PeNCs。通过LMPT方法，红色发射PeNCs的光电特性得到显著改善，在637±2nm发射波长处的光致发光量子产率（PLQY）达到88.7%，载流子寿命从20.77ns增加到31.52ns。我们实现了高效的红色钙钛矿发光二极管，在637±2nm电致发光发射时，最大电流效率为7.69cd/A，外量子效率为6.36%，半高宽为31nm且很窄。
