Electron delocalization and relaxation behavior in Cu-doped B i2S e3 films
Abstract
C uxB i2S e3 is known for superconductivity due to Cu intercalation in the van der Waals gaps between the quintuple layers of B i2S e3 at x >0.10 . Here we report the synthesis and transport properties of Cu-doped C uxB i2S e3 films prepared by the chemical-vapor-deposition (CVD) method with 0.11 ≥x ≥0 . It is found that the insulatinglike temperature-dependent resistivity of polycrystalline C uxB i2S e3 films exhibits a marked metallic downturn and an increase of carrier concentration below ∼37 K. There is also a time-dependent slow relaxation behavior in the resistance at low temperature. These effects might be related to the strong hybridization between C u+ and C u2 + conduction bands from the intercalated C u+ and substituted C u2 + sites in B i2S e3 films. The findings here have important implications for the understanding and development of doping-induced superconductivity in topological insulators.
- Publication:
-
Physical Review B
- Pub Date:
- August 2017
- DOI:
- 10.1103/PhysRevB.96.075152
- Bibcode:
- 2017PhRvB..96g5152L