Kinoshita Kei, Moriya Rai, Okazaki Shota, Zhang Yijin, Masubuchi Satoru, Watanabe Kenji, Taniguchi Takashi, Sasagawa Takao, Machida Tomoki
Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505, Japan.
Laboratory for Materials and Structures, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama, Kanagawa 226-8503, Japan.
Nano Lett. 2022 Jun 22;22(12):4640-4645. doi: 10.1021/acs.nanolett.2c00396. Epub 2022 Jun 5.
We demonstrate van der Waals double quantum well (vDQW) devices based on few-layer WSe quantum wells and a few-layer -BN tunnel barrier. Due to the strong out-of-plane confinement, an exfoliated WSe exhibits quantized subband states at the Γ point in its valence band. Here, we report resonant tunneling and negative differential resistance in vDQW at room temperature owing to momentum- and energy-conserved tunneling between the quantized subbands in each well. Compared to single quantum well (QW) devices with only one QW layer possessing quantized subbands, superior current peak-to-valley ratios were obtained for the DQWs. Our findings suggest a new direction for utilizing few-layer-thick transition metal dichalcogenides in subband QW devices, bridging the gap between two-dimensional materials and state-of-the-art semiconductor QW electronics.
我们展示了基于几层WSe量子阱和几层六方氮化硼（h-BN）隧道势垒的范德华双量子阱（vDQW）器件。由于强面外限制，剥离的WSe在其价带的Γ点处呈现量子化子带态。在此，我们报道了室温下vDQW中的共振隧穿和负微分电阻，这是由于每个阱中量子化子带之间的动量和能量守恒隧穿所致。与仅具有一个拥有量子化子带的量子阱层的单量子阱（QW）器件相比，DQW获得了更高的电流峰谷比。我们的研究结果为在子带量子阱器件中利用几层厚的过渡金属二卤化物指明了一个新方向，弥合了二维材料与最先进的半导体量子阱电子学之间的差距。
