ChemInform Abstract: Electroluminescence at GaN and Ga_xIn_1‐xN Electrodes in Aqueous Electrolytes.

Abstract

1998 luminescence, fluorescence luminescence, fluorescence (solids and liquids) D 6540 -007Electroluminescence at GaN and GaxIn 1−x N Electrodes in Aqueous Electrolytes.-Electroluminescence of single crystal and thin films of GaN and GaxIn 1−x N (x: 0.8) is observed in aqueous solution containing peroxydisulfate on passage of cathodic currents. The resulting emission is compared with the photoluminescence of the same materials on UV light excitation. Only the subbandgap emission is observed for GaN electrodes. The electroluminescence spectra of GaxIn 1−x N only shows a yellow luminescence band at lower applied potentials. When a more negative potential is applied, the near band-edge emission (2.9 eV) appears. -(HUNG, C.-J.; HALAOUI, L. I.; BARD, A. J.; GRUDOWSKI, P. A.; DUPUIS, R. D.; MOLSTAD, J.; DISALVO, F. J.; Electrochem. Solid-State Lett. 1 (1998) 3, 142-144; Dep. Chem. Biochem., Univ. Tex., Austin, TX 78712, USA; EN)

Defect Luminescence at n-GaN Electrodes

“…EL measurements at n-GaN electrodes in aqueous persulfate solutions were also performed by Hung et al 2 They observed a shift of the peak maximum position of the EL spectra from 2.0 eV toward 2.15 eV when the electrode potential was changed from −1 V vs SCE to −5 V vs SCE, which may agree qualitatively with the results presented in this paper.…”

“…Very often, a broad sub-bandgap emission band centered at around 2.2 eV, the so-called yellow luminescence band, is observed. On yellow luminescence in aqueous solutions, only few reports have been published, [1][2][3] despite the fact that performing luminescence experiments in aqueous solutions as a function of the electrode potential may yield useful information on the relative contribution of bulk and surface properties in the consumption of minority carriers.…”

Photoetching Mechanisms of GaN in Alkaline S[sub 2]O[sub 8][sup 2−] Solution

“…Such processes have been observed with GaN and SiC. [21][22][23][24] Huygens et al showed that S 2 O 8 2− was reduced electrochemically at epitaxial GaN in the dark in a H 2 SO 4 solution and that the reaction was kinetically favorable. 23,25 In this paper, we used the results of an electrochemical study of n-type GaN in alkaline solutions of S 2 O 8 2− as a basis for a consideration of the photoetching of the semiconductor.…”