Electrochemical characterization of GaN surface states
Electrochemical characterization of GaN surface states
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GaN 表面态的电化学表征
DOI：
10.1063/1.4995429
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发表时间：
2017
影响因子：
3.2
通讯作者：
M. Stutzmann
中科院分区：
文献类型：
--
作者：
Andrea Winnerl;J. Garrido;M. Stutzmann
在这项工作中，我们提出了一个系统的研究的电化学性质的金属有机化学气相沉积和混合气相外延生长的n型GaN在水溶液中的电解质。为了这个目的，我们在很宽的电位和频率范围内进行循环伏安法和阻抗谱测量，使用纯的水性电解质，并添加两种不同类型的氧化还原对，以及对GaN电极进行不同的表面处理。对于Ga-极性GaN电极，电荷转移到电解质是由表面状态，这是不相关的位错，是独立的具体的生长技术为主。这些表面状态可以通过表面处理进行修改;它们通过在HCl中蚀刻产生，并通过氧化钝化。不同的表面缺陷状态存在于N-极性GaN电极上，其并不显著地有助于跨越GaN/电解质界面的电荷转移。
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.