Surface reconstructions and transport of epitaxial PtLuSb (001) thin films grown by MBE

TL;DR

This study investigates the surface reconstructions and electronic transport properties of epitaxial PtLuSb (001) thin films grown by MBE, revealing stable surface phases, growth conditions, and high-quality film characteristics.

Contribution

It provides the first detailed analysis of surface reconstructions and transport properties of PtLuSb (001) films grown by MBE, including a phase diagram for surface reconstructions.

Findings

Identified (1x3) and c(2x2) surface reconstructions on PtLuSb (001)

Established a growth window at 320-380°C with optimal quality at 380°C

Produced films with low p-type carrier concentrations and high hole mobilities

Abstract

This work presents the surface reconstructions and transport properties of the topological insulator PtLuSb grown on Al0.1In0.9Sb/GaAs (001). Two stable surface reconstructions, (1x3) and c(2x2), were observed on PtLuSb (001) surfaces. Antimony-dimerization was determined to be the nature of the (1x3) surface reconstruction as evidenced by chemical binding energy shifts in the antimony 4d core-level for surface bonding components. The two surface reconstructions were studied as a function of Sb4 overpressure and substrate temperature to create a reconstruction phase diagram. From this reconstruction phase diagram, a growth window from 320 {\deg}C to 380 {\deg}C using an antimony overpressure was identified. Within this window, the highest quality films were grown at a growth temperature of 380 {\deg}C. These films exhibited lower p-type carrier concentrations as well as relatively high hole mobilities.