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Time‐Dependent Electrical Transport Properties of Topological Insulator Cr‐Doped Bi 2 Se 3 Thin Films
Author(s) -
Li Qiu Lin,
Zhang Xing Hua,
Wang Wen Jie,
Li Zhi Qing,
Zhou Ding Bang,
Gao Kuang Hong
Publication year - 2019
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201800735
Subject(s) - dephasing , thin film , weak localization , materials science , topological insulator , electron , doping , condensed matter physics , electron transport chain , electrical resistivity and conductivity , analytical chemistry (journal) , chemistry , nanotechnology , magnetoresistance , physics , optoelectronics , biochemistry , quantum mechanics , chromatography , magnetic field
This paper reports the research of the electrical transport properties of Cr‐doped Bi 2 Se 3 thin films. The films with a uniform Cr distribution exhibit the same structure as undoped Bi 2 Se 3 thin film. At low temperatures, both the weak antilocalization (WAL) and the electron–electron interaction (EEI) effects are observed. From the WAL effect, the dephasing length and the number of the transport channels are extracted. The temperature dependence of the extracted dephasing length can be described by both the Nyquist electron–electron and the electron–phonon scatterings. With increasing time in vacuum, the resistances of the thin films exhibit a transition from the negative to the positive temperature coefficient, with an increase in electron density. Unexpectedly, the number of the transport channels extracted from the WAL effect is found to increase with increasing time, which is further confirmed by analyzing the EEI effect. This observation can be attributed to the presence of two‐dimensional electron gas on the surface of films, which is likely to be formed through the surface reaction with water.