Claire F James, Solomos Marina A, Kim Jungkil, Wang Gaoqiang, Siegler Maxime A, Crommie Michael F, Kempa Thomas J
Department of Chemistry, Johns Hopkins University, Baltimore, MD, USA.
Department of Physics, University of California Berkeley, Berkeley, CA, USA.
Nat Commun. 2020 Nov 2;11(1):5524. doi: 10.1038/s41467-020-19220-y.
The incorporation of metal-organic frameworks into advanced devices remains a desirable goal, but progress is hindered by difficulties in preparing large crystalline metal-organic framework films with suitable electronic performance. We demonstrate the direct growth of large-area, high quality, and phase pure single metal-organic framework crystals through chemical vapor deposition of a dimolybdenum paddlewheel precursor, Mo(INA). These exceptionally uniform, high quality crystals cover areas up to 8600 µm and can be grown down to thicknesses of 30 nm. Moreover, scanning tunneling microscopy indicates that the Mo(INA) clusters assemble into a two-dimensional, single-layer framework. Devices are readily fabricated from single vapor-phase grown crystals and exhibit reversible 8-fold changes in conductivity upon illumination at modest powers. Moreover, we identify vapor-induced single crystal transitions that are reversible and responsible for 30-fold changes in conductivity of the metal-organic framework as monitored by in situ device measurements. Gas-phase methods, including chemical vapor deposition, show broader promise for the preparation of high-quality molecular frameworks, and may enable their integration into devices, including detectors and actuators.
将金属有机框架纳入先进设备仍然是一个理想目标，但由于难以制备具有合适电子性能的大面积结晶金属有机框架薄膜，进展受到阻碍。我们通过二钼桨轮前驱体Mo(INA)的化学气相沉积，展示了大面积、高质量且相纯的单金属有机框架晶体的直接生长。这些异常均匀、高质量的晶体覆盖面积可达8600 µm，并且可以生长到30 nm的厚度。此外，扫描隧道显微镜表明Mo(INA)簇组装成二维单层框架。器件很容易由气相生长的单晶体制备而成，并且在适度功率光照下表现出电导率可逆的8倍变化。此外，我们通过原位器件测量确定了气相诱导的单晶转变，这些转变是可逆的，并且是金属有机框架电导率30倍变化的原因。包括化学气相沉积在内的气相方法，在制备高质量分子框架方面显示出更广阔的前景，并且可能使其能够集成到包括探测器和致动器在内的设备中。
