Photoelectrochemical hydrogen generation using graded In-content InGaN photoelectrode structures. (May 2019)

• Record Type: Journal Article
• Authors: Ohkawa, Kazuhiro; Uetake, Yusuke; Velazquez-Rizo, Martin; Iida, Daisuke
• Is Part Of: Nano energy. Volume 59(2019)
• Page Start: 569
• Page End: 573
• Publication Date: 2019-05
• Subjects: InGaN photoelectrode -- NiO cocatalyst -- Hydrogen generation -- Nitrides -- Metalorganic vapor phase epitaxy -- Graded structure; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2019.03.011
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: We have improved the InGaN/GaN heterointerface to achieve higher energy conversion efficiency by replacing a uniform InGaN layer with a graded In-content InGaN layer. Even In0.08 Ga0.92 N/GaN heterostructure has a large conduction band offset, which is large enough to suppress the photocurrent in the photocatalytic system. The graded In-content InGaN structures were grown by metalorganic vapor-phase epitaxy by changing the TMIn flow rate gradually. X-ray reciprocal space mapping confirmed the graded structures. The graded InGaN/GaN structure significantly increased photocurrent and H2 generation by 50% and more compared with the conventional uniform InGaN/GaN structures. Graphical abstract: Image 1 Highlights: High-quality of graded InGaN layers. Investigation of the effect of the graded InGaN on the photochemical phenomena. The graded InGaN layer is no step-like energy barrier in the conduction band. The graded InGaN/GaN structure significantly increased photocurrent and H2 generation.