Formation of GaN porous structures with improved structural controllability by photoassisted electrochemical etching. (10th March 2016)

• Record Type: Journal Article
• Authors: Kumazaki, Yusuke; Yatabe, Zenji; Sato, Taketomo
• Is Part Of: Japanese journal of applied physics. Volume 55:Number 4(2016:Apr.)Supplement 4
• Publication Date: 2016-03-10
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/JJAP.55.04EJ12
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: We aimed to develop a photoassisted electrochemical etching process for the formation of GaN porous structures. Pore linearity and depth controllability were strongly affected by the anode voltage. In addition, the use of light with an energy below the band gap played an important role in controlling the pore diameter. Spectro-electrochemical measurements revealed that the high electric field induced at the GaN/electrolyte interface caused a redshift of the photoabsorption edge. This specific phenomenon can be explained by a theoretical calculation based on the Franz–Keldysh effect. On the basis of the results of our experimental and theoretical analyze, we propose a formation model for GaN porous structures. We also note that the application of the Franz–Keldysh effect is useful in controlling the structural properties of GaN porous structures.