최신연구동향

TREND OF RESEARCH

  •   >  
  • 연구동향
  •   >  
  • 최신연구동향
제목 [서울대 최근창 학생, 김대식 교수] Nano Letters 논문 게재
출처 서울대학교   날짜 2017-11-01
AUTHORS: Geunchang Choi, Young-Mi Bahk, Taehee Kang, Yoojin Lee, Byung Hee Son, Yeong Hwan Ahn, Minah Seo, and Dai-Sik Kim

ABSTRACT: 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 (∼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 nanoprobing system will open up pathways toward direct and nondestructive measurements of surface dynamics of bulk semiconductors.

이 페이지에서 제공하는 정보에 만족하십니까?