Dynamical observation of photo-Dember effect on semi-insulating GaAs using femtosecond core-level photoelectron spectroscopy. (30th January 2015)

• Record Type: Journal Article
• Authors: Oguri, Katsuya; Tsunoi, Takanobu; Kato, Keiko; Nakano, Hidetoshi; Nishikawa, Tadashi; Tateno, Kouta; Sogawa, Tetsuomi; Gotoh, Hideki
• Is Part Of: Applied physics express. Volume 8:Number 2(2015:Feb.)
• Publication Date: 2015-01-30
• Subjects: Physics -- Periodicals; Technology -- Periodicals; 621.05
• DOI: 10.7567/APEX.8.022401
• Languages: English
• ISSNs: 1882-0778

Abstract

Abstract: We investigated ultrafast photogenerated carrier dynamics on a semi-insulating GaAs surface using femtosecond time-resolved core-level photoelectron spectroscopy. We observed a transient change in the surface potential where the Ga-3d core-level peak instantaneously shifted by ∼350 meV toward a higher binding energy within 2 ps of a 100 fs laser irradiation. A comparison of the experimental results with numerical simulations based on a drift-diffusion model of a semi-insulating semiconductor revealed that the transient surface potential change was mainly due to the photo-Dember effect, whereby the large difference in the carrier diffusion between the electron and hole instantaneously induced a surface photovoltage.