Redshift of A1(longitudinal optical) mode for GaN crystals under strong electric field. (19th December 2017)

• Record Type: Journal Article
• Authors: Gu, Hong; Wu, Kaijie; Zheng, Shunan; Shi, Lin; Zhang, Min; Liu, Zhenghui; Liu, Xinke; Wang, Jianfeng; Zhou, Taofei; Xu, Ke
• Is Part Of: Applied physics express. Volume 11:Number 1(2018)
• Publication Date: 2017-12-19
• Subjects: Physics -- Periodicals; Technology -- Periodicals; 621.05
• DOI: 10.7567/APEX.11.011002
• Languages: English
• ISSNs: 1882-0778

Abstract

Abstract: We investigated the property of GaN crystals under a strong electric field. The Raman spectra of GaN were measured using an ultraviolet laser, and a remarkable redshift of the A 1 (LO) mode was observed. The role of the surface depletion layer was discussed, and the interrelation between the electric field and phonons was revealed. First-principles calculations indicated that, in particular, the phonons that vibrate along the [0001] direction are strongly influenced by the electric field. This effect was confirmed by a surface photovoltage experiment. The results revealed the origin of the redshift and presented the phonon property of GaN under a strong electric field.