Ambipolar transport in van der Waals black arsenic field effect transistors
Ambipolar transport in van der Waals black arsenic field effect transistors
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DOI：
10.1088/1361-6528/ab9d40
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发表时间：
2020-10-02
期刊：
影响因子：
3.5
通讯作者：
Koester, Steven J.
中科院分区：
文献类型：
--
作者：
Golani, Prafful;Yun, Hwanhui;Koester, Steven J.
黑砷（BAs）是一种元素范德华半导体，有望用于广泛的电子和光子应用。窄带隙和对称能带结构表明双极（双极和 p 型）输运应该是可观察到的，然而，迄今为止仅对 p 型输运进行了实验研究。在这里，我们演示并表征了剥离 BA 场效应晶体管的双极输运。在最厚的薄片（类似于 80 nm）中，空穴和电子传导的最大电流 I-max 分别高达 60 mu A mu m(-1) 和 90 mu A mu m(-1)。室温空穴（电子）迁移率高达150 cm(2)V(-1)s(-1)(175 cm(2)V(-1)s(-1))，其温度依赖性与声子散射机制一致。 Ni 接触 BA 的肖特基势垒高度也从与温度相关的测量中提取。发现 n 型和 p 型电导率的 I(max) 随着厚度的减小而减小，而 I(max) 与最小电流 I-min 的比率增加。在最薄的薄片（类似于1.5 nm）中，仅观察到p型电导率，最低值为I（min）= 400 fA mu m（-1）。对于p（n沟道）器件，获得了高达5 x 10（5）（5 x 10（2））的I-max/I（min）比率。最后，利用双极性演示了互补逻辑逆变器和倍频电路。
Black arsenic (BAs) is an elemental van der Waals semiconductor that is promising for a wide range of electronic and photonic applications. The narrow bandgap and symmetric band structure suggest that ambipolar (bothn- andp-type) transport should be observable, however, onlyp-type transport has been experimentally studied to date. Here, we demonstrate and characterize ambipolar transport in exfoliated BAs field effect transistors. In the thickest flakes (similar to 80 nm), maximum currents,I-max, up to 60 mu A mu m(-1)and 90 mu A mu m(-1)are achieved for hole and electron conduction, respectively. Room-temperature hole (electron) mobilities up to 150 cm(2)V(-1)s(-1)(175 cm(2)V(-1)s(-1)) were obtained, with temperature-dependence consistent with a phonon-scattering mechanism. The Schottky barrier height for Ni contacts to BAs was also extracted from the temperature-dependent measurements.I(max)for bothn- andp-type conductivity was found to decrease with reduced thickness, while the ratio ofI(max)to the minimum current,I-min, increased. In the thinnest flakes (similar to 1.5 nm), onlyp-type conductivity was observed with the lowest value ofI(min)= 400 fA mu m(-1).I-max/I(min)ratios as high as 5 x 10(5)(5 x 10(2)) were obtained, forp- (n-channel) devices. Finally, the ambipolarity was used to demonstrate a complementary logic inverter and a frequency doubling circuit.