Liu Shihao, Wang Ying-Chiao, Chang Chi-Ming, Yasuda Takeshi, Fukui Naoya, Maeda Hiroaki, Long Peihua, Nakazato Kazuo, Jian Wen-Bin, Xie Wenfa, Tsukagoshi Kazuhito, Nishihara Hiroshi
WPI International Center for Materials Nanoarchitectonics (WPI-MANA) & International Center for Young Scientists (ICYS), National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan.
Nanoscale. 2020 Apr 3;12(13):6983-6990. doi: 10.1039/d0nr00240b.
Two-dimensional (2D) vdW materials have been integrated into optoelectronic devices to achieve exceptional functionality. However, the integration of large-area 2D thin films into organic light-emitting devices (OLEDs) remains challenging because of the finite number of inorganic 2D materials and the high-temperature requirements of their deposition process. The construction of 2D organometallic materials holds immense potential because of their solution synthesis and unlimited structural and functional diversity. Here, we report a facile route using an oil-water interfacial coordination reaction between organic ligands and divalent metal ions to synthesize crystalline quasi-2D organometallic bis(dithiolato)nickel (NiDT) nanosheets with a centimeter scale and a tunable thickness. The NiDT nanosheets can be directly integrated into OLEDs for use as a hole buffer layer and a fluorescent mounting medium without the aid of a transfer process. Moreover, OLEDs with NiDT nanosheets show not only comparable efficiency to conventional OLEDs but also prolonged device lifetime by nearly 2 times. These results open up a new dimension to use quasi-2D organometallic nanosheets as functional layers in large-area organic devices.
二维（2D）范德华材料已被集成到光电器件中以实现卓越的功能。然而，由于无机二维材料数量有限及其沉积过程对高温的要求，将大面积二维薄膜集成到有机发光器件（OLED）中仍然具有挑战性。二维有机金属材料的构建具有巨大潜力，因为它们可以通过溶液合成，并且具有无限的结构和功能多样性。在此，我们报告了一种简便的方法，利用有机配体与二价金属离子之间的油水界面配位反应，合成具有厘米级尺寸和可调厚度的结晶准二维有机金属双（二硫醇）镍（NiDT）纳米片。NiDT纳米片无需转移过程即可直接集成到OLED中，用作空穴缓冲层和荧光固定介质。此外，具有NiDT纳米片的OLED不仅显示出与传统OLED相当的效率，而且器件寿命延长了近两倍。这些结果为在大面积有机器件中使用准二维有机金属纳米片作为功能层开辟了新的维度。
