Kwon Sung-Joo, Ahn Soyeong, Heo Jung-Min, Kim Dong Jin, Park Jinwoo, Lee Hae-Ryung, Kim Sungjin, Zhou Huanyu, Park Min-Ho, Kim Young-Hoon, Lee Wanhee, Sun Jeong-Yun, Hong Byung Hee, Lee Tae-Woo
Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Gyungbuk 790-784, Republic of Korea.
Department of Materials Science and Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
ACS Appl Mater Interfaces. 2021 Feb 24;13(7):9074-9080. doi: 10.1021/acsami.0c12939. Epub 2021 Jan 25.
Graphene is an optimal material to be employed as an ionic diffusion barrier because of its outstanding impermeability and chemical robustness. Indium tin oxide (ITO) is often used in perovskite light-emitting diodes (PeLEDs), and it can release indium easily upon exposure to the acidic hole-injection layer so that luminescence can be quenched significantly. Here, we exploit the outstanding impermeability of graphene and use it as a chemical barrier to block the etching that can occur in ITO exposed to an acidic hole-injection layer in PeLEDs. This barrier reduced the luminescence quenching that these metallic species can cause, so the photoluminescence lifetime of perovskite film was substantially higher in devices with ITO and graphene layer (87.9 ns) than in devices that had only an ITO anode (22.1 ns). Luminous current efficiency was also higher in PeLEDs with a graphene barrier (16.4 cd/A) than in those without graphene (9.02 cd/A). Our work demonstrates that graphene can be used as a barrier to reduce the degradation of transparent electrodes by chemical etching in optoelectronic devices.
由于石墨烯具有出色的不透性和化学稳定性，它是用作离子扩散阻挡层的理想材料。氧化铟锡（ITO）常用于钙钛矿发光二极管（PeLED）中，并且在暴露于酸性空穴注入层时容易释放铟，从而导致发光显著猝灭。在此，我们利用石墨烯出色的不透性，并将其用作化学阻挡层，以阻止在PeLED中暴露于酸性空穴注入层的ITO中可能发生的蚀刻。这种阻挡层减少了这些金属物种可能导致的发光猝灭，因此在具有ITO和石墨烯层的器件中，钙钛矿薄膜的光致发光寿命（87.9 ns）比仅具有ITO阳极的器件（22.1 ns）长得多。具有石墨烯阻挡层的PeLED的发光电流效率（16.4 cd/A）也高于没有石墨烯的PeLED（9.02 cd/A）。我们的工作表明，石墨烯可以用作阻挡层，以减少光电器件中化学蚀刻对透明电极的降解。
