Electrochemical characterization of GaN surface states
Winnerl, Andrea (Technische Universität München. Physik Department)
Garrido, Jose (Institut Català de Nanociència i Nanotecnologia)
Stutzmann, Martin (Walter Schottky Institut)

Date:	2017
Abstract:	In this work, we present a systematic study of the electrochemical properties of metal-organic chemical vapor deposition and hybrid vapor phase epitaxy grown n-type GaN in aqueous electrolytes. For this purpose, we perform cyclic voltammetry and impedance spectroscopy measurements over a wide range of potentials and frequencies, using a pure aqueous electrolyte and adding two different types of redox couples, as well as applying different surface treatments to the GaN electrodes. For Ga-polar GaN electrodes, the charge transfer to an electrolyte is dominated by surface states, which are not related to dislocations and are independent of the specific growth technique. These surface states can be modified by the surface treatment; they are generated by etching in HCl and are passivated by oxidation. Different surface defect states are present on N-polar GaN electrodes which do not significantly contribute to the charge transfer across the GaN/electrolyte interface.
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Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Aqueous electrolyte ; Electrochemical characterizations ; Growth techniques ; Hybrid vapor phase epitaxies ; Impedance spectroscopy measurements ; Metal organic ; Surface defect state ; Systematic study
Published in:	Journal of applied physics, Vol. 122, issue 4 (July 2017) , art. 45302, ISSN 1089-7550

DOI: 10.1063/1.4995429

13 p, 3.1 MB

The record appears in these collections:
Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles