TY - JOUR
T1 - Epitaxial growth of PbSe few-layers on SrTiO3
T2 - The effect of compressive strain and potential two-dimensional topological crystalline insulator
AU - Shao, Zhibin
AU - Zheng, Fawei
AU - Zhang, Zongyuan
AU - Sun, Haigen
AU - Li, Shaojian
AU - Yuan, Hui
AU - Li, Qing
AU - Zhang, Ping
AU - Pan, Minghu
N1 - Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/2/26
Y1 - 2019/2/26
N2 - The freestanding PbSe monolayer has been predicted as a candidate of the two-dimensional topological crystalline insulator, which possesses the Dirac-cone-like edge states resided at the edge. Up to now, however, direct experimental evidence of topological PbSe monolayer has not yet been reported. Here, we report the epitaxial growth and scanning tunneling microscopy study of few-layers PbSe islands grown on SrTiO3 substrate. From the investigation of different thickness, we discover the release of compressive strain and the reduction of bandgap as the thickness becomes thick. Following detailed spectroscopic measurements, a signature of Dirac-like edge states is observed at the edge of seventh-layer PbSe. In conjunction with first-principle calculations, we find that compressive-strain-induced buckling adjusts the topological band inversion and eventually leads to a phase transition from nontrivial two-dimensional topological crystalline insulator to trivial insulator, which match well with our experimental observations. Therefore, both theoretical calculations and experimental observations reveal that the strain can effectively affect the property of epitaxial PbSe, meanwhile demonstrate seventh-layer PbSe as a potential candidate of 2D TCI.
AB - The freestanding PbSe monolayer has been predicted as a candidate of the two-dimensional topological crystalline insulator, which possesses the Dirac-cone-like edge states resided at the edge. Up to now, however, direct experimental evidence of topological PbSe monolayer has not yet been reported. Here, we report the epitaxial growth and scanning tunneling microscopy study of few-layers PbSe islands grown on SrTiO3 substrate. From the investigation of different thickness, we discover the release of compressive strain and the reduction of bandgap as the thickness becomes thick. Following detailed spectroscopic measurements, a signature of Dirac-like edge states is observed at the edge of seventh-layer PbSe. In conjunction with first-principle calculations, we find that compressive-strain-induced buckling adjusts the topological band inversion and eventually leads to a phase transition from nontrivial two-dimensional topological crystalline insulator to trivial insulator, which match well with our experimental observations. Therefore, both theoretical calculations and experimental observations reveal that the strain can effectively affect the property of epitaxial PbSe, meanwhile demonstrate seventh-layer PbSe as a potential candidate of 2D TCI.
KW - Compression strain
KW - First-principle calculation
KW - Molecular beam epitaxy
KW - Pbse islands
KW - Scanning tunneling microscopy/spectroscopy
KW - Structural buckling
UR - http://www.scopus.com/inward/record.url?scp=85061481215&partnerID=8YFLogxK
U2 - 10.1021/acsnano.9b00072
DO - 10.1021/acsnano.9b00072
M3 - Article
C2 - 30707554
AN - SCOPUS:85061481215
SN - 1936-0851
VL - 13
SP - 2615
EP - 2623
JO - ACS Nano
JF - ACS Nano
IS - 2
ER -