Bisswanger Timo, Winter Zachary, Schmidt Anne, Volmer Frank, Watanabe Kenji, Taniguchi Takashi, Stampfer Christoph, Beschoten Bernd
2nd Institute of Physics and JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany.
Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
Nano Lett. 2022 Jun 22;22(12):4949-4955. doi: 10.1021/acs.nanolett.2c01119. Epub 2022 Jun 1.
We present inverted spin-valve devices fabricated from chemical vapor deposition (CVD)-grown bilayer graphene (BLG) that show more than a doubling in device performance at room temperature compared to state-of-the-art bilayer graphene spin valves. This is made possible by a polydimethylsiloxane droplet-assisted full-dry transfer technique that compensates for previous process drawbacks in device fabrication. Gate dependent Hanle measurements reveal spin lifetimes of up to 5.8 ns and a spin diffusion length of up to 26 μm at room temperature combined with a charge carrier mobility of about 24 000 cm(V s) for the best device. Our results demonstrate that CVD-grown BLG shows equally good room temperature spin transport properties as both CVD-grown single-layer graphene and even exfoliated single-layer graphene.
我们展示了由化学气相沉积（CVD）生长的双层石墨烯（BLG）制成的倒置自旋阀器件，与最先进的双层石墨烯自旋阀相比，该器件在室温下的性能提高了一倍多。这是通过聚二甲基硅氧烷液滴辅助的全干法转移技术实现的，该技术弥补了器件制造中先前工艺的缺点。栅极相关的汉勒测量显示，在室温下，最佳器件的自旋寿命高达5.8 ns，自旋扩散长度高达26 μm，同时电荷载流子迁移率约为24000 cm²/（V·s）。我们的结果表明，CVD生长的BLG表现出与CVD生长的单层石墨烯甚至剥离的单层石墨烯同样良好的室温自旋输运特性。
