Kim Nakyung, Shin Mingue, Jun Seongmoon, Choi Bongjun, Kim Joonyun, Park Jinu, Kim Hyunseung, Jung Woochul, Lee Jung-Yong, Cho Yong-Hoon, Shin Byungha
Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
ACS Appl Mater Interfaces. 2021 Aug 11;13(31):37323-37330. doi: 10.1021/acsami.1c05447. Epub 2021 Jul 31.
Highly efficient vacuum-deposited CsPbBr perovskite light-emitting diodes (PeLEDs) are demonstrated by introducing a separate polyethylene oxide (PEO) passivation layer. A CsPbBr film deposited on the PEO layer via thermal co-evaporation of CsBr and PbBr exhibits an almost 50-fold increase in photoluminescence quantum yield intensity compared to a reference sample without PEO. This enhancement is attributed to the passivation of interfacial defects of the perovskite, as evidenced by temperature-dependent photoluminescence measurements. However, direct application of PEO to an LED device is challenging because of the electrically insulating nature of PEO. This issue is solved by doping PEO layers with MgCl. This strategy results in an enhanced luminance and external quantum efficiency (EQE) of up to 6887 cd m and 7.6%, respectively. To the best of our knowledge, this is the highest EQE reported to date among vacuum-deposited PeLEDs.
通过引入单独的聚环氧乙烷（PEO）钝化层，展示了高效的真空沉积CsPbBr钙钛矿发光二极管（PeLED）。通过CsBr和PbBr的热共蒸发沉积在PEO层上的CsPbBr薄膜，与没有PEO的参考样品相比，光致发光量子产率强度几乎提高了50倍。这种增强归因于钙钛矿界面缺陷的钝化，这通过温度相关的光致发光测量得到证实。然而，由于PEO的电绝缘性质，将PEO直接应用于LED器件具有挑战性。通过用MgCl掺杂PEO层解决了这个问题。这种策略分别导致高达6887 cd m和7.6%的亮度增强和外量子效率（EQE）。据我们所知，这是迄今为止在真空沉积的PeLED中报道的最高EQE。
