Due to the intrinsic spontaneous and piezoelectric polarization effect, III-nitride semiconductor heterostructures are promising candidates for generating 2D electron gas (2DEG) system. Among III-nitrides, InN is predicted to be the best conductive-channel material because its electrons have the smallest effective mass and it exhibits large band offsets at the heterointerface of GaN/InN or AlN/InN. Until now, that prediction has remained theoretical, due to a giant gap between the optimal growth windows of InN and GaN, and the difficult epitaxial growth of InN in general. The experimental realization of 2DEG at an InGaN/InN heterointerface grown by molecular beam epitaxy is reported here. The directly probed electron mobility and the sheet electron density of the InGaN/InN heterostructure are determined by Hall-effect measurements at room temperature to be 2.29 × 103 cm2 V−1 s−1 and 2.14 × 1013 cm−2, respectively, including contribution from the InN bottom layer. The Shubnikov–de Haas results at 3 K confirm that the 2DEG has an electron density of 3.30 × 1012 cm−2 and a quantum mobility of 1.48 × 103 cm2 V−1 s−1. The experimental observations of 2DEG at the InGaN/InN heterointerface have paved the way for fabricating higher-speed transistors based on an InN channel.
|Original language||English (US)|
|State||Published - Sep 2018|
Bibliographical noteFunding Information:
This work was partly supported by the National Key R&D Program of China (No. 2016YFB0400100), the Science Challenge Project (No. TZ2016003-2), the National Natural Science Foundation of China (Nos. 61734001, 61521004, 61674010), NSAF (No. U1630109), and by the King Abdullah University of Science and Technology (KAUST). The authors are grateful to Prof. Yanwu Xie, Yan Wen, and Lixian Wang for fruitful discussions.
© 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
- 2D electron gas
- molecular beam epitaxy
ASJC Scopus subject areas
- Medicine (miscellaneous)
- Chemical Engineering(all)
- Materials Science(all)
- Biochemistry, Genetics and Molecular Biology (miscellaneous)
- Physics and Astronomy(all)