Choi, Geunchang Bahk, Young-Mi Kang, Taehee Lee, Yoojin Son, Byung Hee Ahn, Yeong Hwan Seo, Minah Kim, Dai-Sik 2024-01-20T00:31:47Z 2024-01-20T00:31:47Z 2021-09-05 2017-10 1530-6984 https://pubs.kist.re.kr/handle/201004/122233 Most semiconductors have surface dynamics radically different from its bulk counterpart due to surface defect, doping level, and symmetry breaking. Because of the technical challenge of direct observation of the surface carrier dynamics, however, experimental studies have been allowed in severely shrunk structures including nanowires, thin films, or quantum wells where the surface-to-volume ratio is very high. Here, we develop a new type of terahertz (THz) nanoprobing system to investigate the surface dynamics of bulk semiconductors, using metallic nanogap accompanying strong THz field confinement. We observed that carrier lifetimes of InP and GaAs dramatically decrease close to the limit of THz time resolution (similar to 1 ps) as the gap size decreases down to nanoscale and that they return to their original values once the nanogap patterns are removed. Our THz narioprobing system will open up pathways toward direct and nondestructive measurements of surface dynamics of bulk semiconductors. English AMER CHEMICAL SOC CARRIER DYNAMICS FIELD ENHANCEMENT GAAS RECOMBINATION INP PHOTOCONDUCTIVITY Terahertz Nanoprobing of Semiconductor Surface Dynamics Article 10.1021/acs.nanolett.7b03289 1 NANO LETTERS, v.17, no.10, pp.6397 - 6401 NANO LETTERS 17 10 6397 6401 scie scopus 000413057500075 2-s2.0-85031292765 Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Science & Technology - Other Topics Materials Science Physics Article CARRIER DYNAMICS FIELD ENHANCEMENT GAAS RECOMBINATION INP PHOTOCONDUCTIVITY Nanoprobing optical pump-terahertz probe spectroscopy semiconductor surface carrier dynamics