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Published Online: 04 June 1998
Accepted: February 1998

Two-dimensional electron gas formed in a back-gated undoped heterostructure

Appl. Phys. Lett. 72, 1745 (1998); https://doi.org/10.1063/1.121171
Y. Hirayama, K. Muraki, and T. Saku
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  • NTT Basic Research Laboratories, 3-1 Morinosato-Wakamiya, Atsugi-shi, Kanagawa 243-0198, Japan
ABSTRACT
By using a back-gate operation, a high-quality two-dimensional electron gas (2DEG) is formed in an undoped GaAs/AlGaAs inverted heterostructure. A high mobility of around 3×106 cm2/V s at 1.6 K is obtained for the structure without any compensating surface doping. The electron density is controllable down to 7×109 cm−2. The relation between electron density and mobility is studied for samples both with and without a surface gate. The obtained results indicate that background impurities and an inhomogeneity of the electric field coming from the surface govern the mobility in a low-electron-density region and that the interface inhomogeneity becomes important at a high electron density.

REFERENCES
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  1. © 1998 American Institute of Physics.

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