BROWSE

ITEM VIEW & DOWNLOAD

Picosecond Competing Dynamics of Apparent Semiconducting-Metallic Phase Transition in the Topological Insulator Bi2Se3

Cited 0 time in webofscience Cited 0 time in scopus
463 Viewed 0 Downloaded
Title
Picosecond Competing Dynamics of Apparent Semiconducting-Metallic Phase Transition in the Topological Insulator Bi2Se3
Author(s)
Sim, Sangwan; Lee, Seungmin; Moon, Jisoo; In, Chihun; Lee, Jekwan; Noh, Minji; Kim, Jehyun; Jang, Woosun; Soonyoung Cha; Seo, Seung Young; Oh, Seongshik; Kim, Dohun; Soon, Aloysius; Moon-Ho Jo; Choi, Hyunyong
Subject
apparent phase transition, ; terahertz spectroscopy, ; topological insulator, ; ultrafast spectroscopy
Publication Date
2020-03
Journal
ACS PHOTONICS, v.7, no.3, pp.759 - 764
Publisher
AMER CHEMICAL SOC
Abstract
© 2020 American Chemical Society. Resolving the complex interplay between surface and bulk response is a long-standing issue in the topological insulators (TIs). Some studies have reported surface-dominated metallic responses, yet others show semiconducting-like bulk photoconductance. Using ultrafast terahertz spectroscopy with the advent of Fermi-level engineered TIs, we discovered that such difference arises from the time-dependent competing process of two parameters, namely, the Dirac-carrier surface scattering rate and the bulk Drude weight. After infrared femtosecond pulse excitation, we observed a metal-like photoconductance reduction for the prototypical n-type Bi2Se3 and a semiconductor-like increased photoconductance for the p-type Bi2Se3. Surprisingly, the bulk-insulating Bi2Se3, which is presumably similar to graphene, exhibits a semiconducting-to-metallic phase apparent transition at 10 ps. The sign-reversed, yet long-lasting (≥500 ps) metallic photoconductance was observed only in the bulk-insulating Bi2Se3, indicating that such dynamic phase transition is governed by the time-dependent competing interplay between the surface scattering rate and the bulk Drude weight. Our observations illustrate new photophysical phenomena of the photoexcited-phase transition in TIs and demonstrate entirely distinct dynamics compared to graphene and conventional gapped semiconductors
URI
https://pr.ibs.re.kr/handle/8788114/8336
DOI
10.1021/acsphotonics.9b01603
ISSN
2330-4022
Appears in Collections:
Center for Artificial Low Dimensional Electronic Systems(원자제어 저차원 전자계 연구단) > 1. Journal Papers (저널논문)
Files in This Item:
There are no files associated with this item.

qrcode

  • facebook

    twitter

  • Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.
해당 아이템을 이메일로 공유하기 원하시면 인증을 거치시기 바랍니다.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Browse