Semiconductor–metal transition in Bi2Se3 caused by impurity doping
Abstract Doping a typical topological insulator, Bi 2 Se 3 , with Ag impurity causes a semiconductor–metal (S-M) transition at 35 K. To deepen the understanding of this phenomenon, structural and transport properties of Ag-doped Bi 2 Se 3 were studied. Single-crystal X-ray diffraction (SC-XRD) showe...
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Published in | Scientific reports Vol. 13; no. 1; pp. 537 - 10 |
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Main Authors | , , , , , , , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
London
Nature Publishing Group
11.01.2023
Nature Publishing Group UK Nature Portfolio |
Subjects | |
Online Access | Get full text |
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Summary: | Abstract
Doping a typical topological insulator, Bi
2
Se
3
, with Ag impurity causes a semiconductor–metal (S-M) transition at 35 K. To deepen the understanding of this phenomenon, structural and transport properties of Ag-doped Bi
2
Se
3
were studied. Single-crystal X-ray diffraction (SC-XRD) showed no structural transitions but slight shrinkage of the lattice, indicating no structural origin of the transition. To better understand electronic properties of Ag-doped Bi
2
Se
3
, extended analyses of Hall effect and electric-field effect were carried out. Hall effect measurements revealed that the reduction of resistance was accompanied by increases in not only carrier density but carrier mobility. The field-effect mobility is different for positive and negative gate voltages, indicating that the
E
F
is located at around the bottom of the bulk conduction band (BCB) and that the carrier mobility in the bulk is larger than that at the bottom surface at all temperatures. The pinning of the
E
F
at the BCB is found to be a key issue to induce the S-M transition, because the transition can be caused by depinning of the
E
F
or the crossover between the bulk and the top surface transport. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 2045-2322 2045-2322 |
DOI: | 10.1038/s41598-023-27701-5 |