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Title: Electrochemical removal of hydrogen atoms in Mg-doped GaN epitaxial layers

Hydrogen atoms inside of an Mg-doped GaN epitaxial layer were effectively removed by the electrochemical potentiostatic activation (EPA) method. The role of hydrogen was investigated in terms of the device performance of light-emitting diodes (LEDs). The effect of the main process parameters for EPA such as solution type, voltage, and time was studied and optimized for application to LED fabrication. In optimized conditions, the light output of 385-nm LEDs was improved by about 26% at 30 mA, which was caused by the reduction of the hydrogen concentration by ∼35%. Further removal of hydrogen seems to be involved in the breaking of Ga-H bonds that passivate the nitrogen vacancies. An EPA process with high voltage breaks not only Mg-H bonds that generate hole carriers but also Ga-H bonds that generate electron carriers, thus causing compensation that impedes the practical increase of hole concentration, regardless of the drastic removal of hydrogen atoms. A decrease in hydrogen concentration affects the current-voltage characteristics, reducing the reverse current by about one order and altering the forward current behavior in the low voltage region.
Authors:
; ; ;  [1] ;  [2] ;  [3] ; ;  [4]
  1. Department of Materials Science and Engineering, and Optoelectronics Convergence Research Center, Chonnam National University, Gwangju 500-757 (Korea, Republic of)
  2. Department of Physics and Optoelectronics Convergence Research Center, Chonnam National University, Gwangju 500-757 (Korea, Republic of)
  3. Korea Photonics Technology Institute, Gwangju 500-460 (Korea, Republic of)
  4. School of Semiconductor and Chemical Engineering, Semiconductor Physics Research Center, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22410195
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 18; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ATOMS; CHARGE CARRIERS; CONCENTRATION RATIO; DOPED MATERIALS; ELECTRIC POTENTIAL; ELECTROCHEMISTRY; ELECTRONS; EPITAXY; GALLIUM NITRIDES; HOLES; HYDROGEN; LAYERS; LIGHT EMITTING DIODES; MAGNESIUM COMPOUNDS; NITROGEN; VACANCIES; VISIBLE RADIATION