Designer Topological Insulator with Enhanced Gap and Suppressed Bulk Conduction in BiSe/SbTe Ultrashort-Period Superlattices.

A novel approach to suppress bulk conductance in three-dimensional (3D) topological insulators (TIs) using short-period superlattices (SLs) of two TIs is presented. Evidence for superlattice gap enhancement (SGE) was obtained from the reduction of bulk background doping from 1.2 × 10 cm to 8.

Self-assembled Bismuth Selenide (BiSe) quantum dots grown by molecular beam epitaxy.

We report the growth of self-assembled BiSe quantum dots (QDs) by molecular beam epitaxy on GaAs substrates using the droplet epitaxy technique. The QD formation occurs after anneal of Bismuth droplets under Selenium flux. Characterization by atomic force microscopy, scanning electron microscopy, X-ray diffraction, high-resolution transmission electron microscopy and X-ray reflectance spectroscopy is presented.

BiSe van der Waals Virtual Substrates for II-VI Heterostructures.

We report on the growth and characterization of optical quality multiple quantum well structures of Zn Cd Se/Zn Cd Mg Se on an ultra-thin BiSe/CdTe virtual substrate on c-plane AlO (sapphire). Excellent quality highly oriented films grown along the (111) direction were achieved as evidenced by reflection high energy electron diffraction and X-ray diffraction studies. We also observed room temperature and 77 K photoluminescence emission with peak energies at 77 K of 2.