†Solid State Physics and Nanometer Structure Consortium (nmC@LU), Lund University, Box 118, S-22100 Lund, Sweden.
‡School of Physics, The University of New South Wales, Sydney, New South Wales 2052, Australia.
ACS Nano. 2015 Jul 28;9(7):7033-40. doi: 10.1021/acsnano.5b01495. Epub 2015 Jun 26.
In semiconductor heterostructures with a type II band alignment, such as GaSb-InAs, conduction can be tuned from electron- to hole-dominated using an electrostatic gate. However, traditional conductance measurements give no direct information on the carrier type, and thus limit the ability to distinguish transport effects originating from the two materials. Here, we employ thermovoltage measurements to GaSb/InAs core-shell nanowires, and reliably identify the dominant carrier type at room temperature as well as in the quantum transport regime at 4.2 K, even in cases where the conductance measurement does not allow for such a distinction. In addition, we show that theoretical modeling using the conductance data as input can reproduce the measured thermovoltage under the assumption that electron and hole states shift differently in energy with the applied gate voltage.
在具有 II 型能带排列的半导体异质结构中，例如 GaSb-InAs，可以使用静电门从电子主导调节到空穴主导。然而，传统的电导测量无法直接提供载流子类型的信息，从而限制了区分两种材料起源的传输效应的能力。在这里，我们在 GaSb/InAs 核壳纳米线中采用热电压测量，并在室温下以及在 4.2 K 的量子输运 regime 中可靠地识别出主导载流子类型，即使在电导测量不允许这种区分的情况下也是如此。此外，我们表明，使用作为输入的电导数据进行的理论建模可以在假设电子和空穴状态随施加的栅极电压以不同的能量移动的情况下再现测量的热电压。
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