These two authors contributed equally to this work.
UV-illuminated dielectrophoresis by two-dimensional electron gas (2DEG) in AlGaN/GaN heterojunction
Article first published online: 27 AUG 2012
Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
physica status solidi (a)
Volume 209, Issue 11, pages 2223–2228, November 2012
How to Cite
Fu, J., Luo, Y., Yobas, L. and Chen, K. J. (2012), UV-illuminated dielectrophoresis by two-dimensional electron gas (2DEG) in AlGaN/GaN heterojunction. Phys. Status Solidi A, 209: 2223–2228. doi: 10.1002/pssa.201228042
- Issue published online: 19 NOV 2012
- Article first published online: 27 AUG 2012
- Manuscript Accepted: 13 JUL 2012
- Manuscript Revised: 5 JUL 2012
- Manuscript Received: 16 JAN 2012
- two-dimensional electron gas
Dielectrophoresis (DEP) induced by activating a patterned two-dimensional electron gas (2DEG) at the interface of compound semiconductor AlGaN/GaN heterojunction has been demonstrated for the first time in our previous work. Briefly, with a peak voltage of ±10 V and a frequency from 100 kHz to 1 MHz, characteristics of both positive and negative DEP have been observed successfully manipulating 2 µm polystyrene microspheres in a drop of deionized (DI) water (pH ∼ 7 and conductivity 1 × 10−4 S m−1) over castellated 2DEG electrodes separated by critical dimensions 50 and 150 µm. This study reports a peculiar observation encountered when performing the DEP experiments under ultraviolet (UV) radiation: The microspheres have been repelled from the 2DEG electrodes yet remained on the surface during pDEP and then levitated upon switching to nDEP. This behavior is not observed in DEP with conventional microelectrodes and explained here by the UV-induced electron–hole generation and the subsequent charge redistribution in the AlGaN/GaN heterostructure.