National High Magnetic Field Laboratory, Florida State University , Tallahassee, Florida 32310, United States.
ACS Nano. 2014 Aug 26;8(8):7923-9. doi: 10.1021/nn501693d. Epub 2014 Jul 14.
We report a room temperature study on the electrical response of field-effect transistors (FETs) based on few-layered MoSe2, grown by a chemical vapor transport technique, mechanically exfoliated onto SiO2. In contrast to previous reports on MoSe2 FETs electrically contacted with Ni, MoSe2 FETs electrically contacted with Ti display ambipolar behavior with current on to off ratios up to 10(6) for both hole and electron channels when applying a small excitation voltage. A rather small hysteresis is observed when sweeping the back-gate voltage between positive and negative values, indicating the near absence of charge "puddles". For both channels the Hall effect indicates Hall mobilities μH ≃ 250 cm(2)/(V s), which are comparable to the corresponding field-effect mobilities, i.e., μFE ∼ 150 to 200 cm(2)/(V s) evaluated through the conventional two-terminal field-effect configuration. Therefore, our results suggest that MoSe2 could be a good candidate for p-n junctions composed of a single atomic layer and for low-power, complementary logic applications.
我们报告了一项基于化学气相输运技术生长的、通过机械剥离在 SiO2 上的少层 MoSe2 的室温场效应晶体管（FET）的电响应研究。与之前报道的 Ni 接触的 MoSe2 FET 不同，当施加小激励电压时，与 Ti 接触的 MoSe2 FET 表现出双极性行为，空穴和电子通道的电流比高达 10(6)。当在正、负栅极电压之间扫掠时，观察到相当小的滞后，表明电荷“水坑”几乎不存在。对于两个通道，霍尔效应表明霍尔迁移率 μH ≃ 250 cm(2)/(V s)，与相应的场效应迁移率相当，即通过传统的两端场效应配置评估的 μFE ∼ 150 至 200 cm(2)/(V s)。因此，我们的结果表明，MoSe2 可能是由单个原子层组成的 p-n 结以及低功率、互补逻辑应用的良好候选材料。
