Research output: Contribution to journal › Article › peer-review
Transport properties of (Bi, Sb)2Te3 topological insulator crystals with lateral p-n junction. / Golyashov, V. A.; Kokh, K. A.; Tereshchenko, O. E.
In: Physical Review Materials, Vol. 7, No. 12, 124204, 12.2023.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Transport properties of (Bi, Sb)2Te3 topological insulator crystals with lateral p-n junction
AU - Golyashov, V. A.
AU - Kokh, K. A.
AU - Tereshchenko, O. E.
N1 - The research was funded by the Ministry of Science and Higher Education of the Russian Federation, Grant No. 075-15-2020-797 (13.1902.21.0024). Публикация для корректировки.
PY - 2023/12
Y1 - 2023/12
N2 - High-quality low-bulk-carrier-concentration 3D topological insulator crystals and films are required for the majority of their potential applications. Creating a p-n transition using composition grading is one of the ways to obtain compensated regions in the bulk of 3D topological insulator crystals. Eventual formation of a p-n junction in 3D topological insulator surface states is expected to enhance the surface-transport-related spin filtering and charge-to-spin conversion. Here we report a detailed study of the transport and surface electronic structure of composition-graded Bi2Te3 and Bi1.34Sb0.66Te3 single crystals with built-in lateral p-n transition. The defect compensation naturally achieved at the p-n interface results in a strong reduction of the bulk carrier concentrations in both crystals. In the Bi2Te3 crystal a high-mobility n-type conductivity region is formed with electron Hall mobility of 70 000 cm2V-1s-1 and Hall concentration of 2×1018cm-3 at 4.2 K. In the Bi1.34Sb0.66Te3 crystal the region of intrinsic conductivity with the lowest observed hole Hall concentration of 6×1017cm-3 and hole Hall mobility of 10 000 cm2V-1s-1 is formed in the vicinity of the p-n junction. The downward band bending was observed on the surface of the p-type conductivity region of the Bi2Te3 and Bi1.34Sb0.66Te3, providing an almost barrierless topological surface state electron channel with no topological p-n junction formed. The composition grading can be used as a reliable method of obtaining high-quality single crystals with relatively large areas of low bulk carrier concentrations and enhanced charge carrier mobility, which can be used in further nanoscale topological insulator device fabrication.
AB - High-quality low-bulk-carrier-concentration 3D topological insulator crystals and films are required for the majority of their potential applications. Creating a p-n transition using composition grading is one of the ways to obtain compensated regions in the bulk of 3D topological insulator crystals. Eventual formation of a p-n junction in 3D topological insulator surface states is expected to enhance the surface-transport-related spin filtering and charge-to-spin conversion. Here we report a detailed study of the transport and surface electronic structure of composition-graded Bi2Te3 and Bi1.34Sb0.66Te3 single crystals with built-in lateral p-n transition. The defect compensation naturally achieved at the p-n interface results in a strong reduction of the bulk carrier concentrations in both crystals. In the Bi2Te3 crystal a high-mobility n-type conductivity region is formed with electron Hall mobility of 70 000 cm2V-1s-1 and Hall concentration of 2×1018cm-3 at 4.2 K. In the Bi1.34Sb0.66Te3 crystal the region of intrinsic conductivity with the lowest observed hole Hall concentration of 6×1017cm-3 and hole Hall mobility of 10 000 cm2V-1s-1 is formed in the vicinity of the p-n junction. The downward band bending was observed on the surface of the p-type conductivity region of the Bi2Te3 and Bi1.34Sb0.66Te3, providing an almost barrierless topological surface state electron channel with no topological p-n junction formed. The composition grading can be used as a reliable method of obtaining high-quality single crystals with relatively large areas of low bulk carrier concentrations and enhanced charge carrier mobility, which can be used in further nanoscale topological insulator device fabrication.
UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85180552207&origin=inward&txGid=92d15405b07e34cf9a64159b5edc8bb9
UR - https://www.mendeley.com/catalogue/8324d5c6-f1e6-3325-8504-b09d640a99ef/
U2 - 10.1103/PhysRevMaterials.7.124204
DO - 10.1103/PhysRevMaterials.7.124204
M3 - Article
VL - 7
JO - Physical Review Materials
JF - Physical Review Materials
SN - 2475-9953
IS - 12
M1 - 124204
ER -
ID: 59543464