Self-assembled ErSb nanostructures of tunable shape and orientation: growth and plasmonic properties

TL;DR

This study demonstrates the controlled growth of ErSb nanostructures with tunable shapes and orientations within a GaSb matrix, and analyzes their plasmonic properties across a broad frequency range using polarization-resolved spectroscopy.

Contribution

It introduces a method to control the shape and orientation of ErSb nanostructures during growth and characterizes their plasmonic responses with theoretical modeling.

Findings

Nanostructure shape and orientation are tunable via Er fraction.

Plasmonic properties are characterized from 100 GHz to 300 THz.

Maxwell-Garnett theory models the polarization-sensitive response.

Abstract

Self-assembled, semimetallic ErSb single crystal nanostructures, grown by molecular beam epitaxy, are embedded within a semiconductor GaSb matrix. Formation, evolution and orientation of a variety of nanostructures, including spherical nanoparticles, elongated nanorods, octagonal shaped nanowires oriented along the surface normal and nanowires oriented in the growth plane, are controlled simply by the Er fraction. The plasmonic properties of the semimetal/semiconductor composites are characterized and quantified by three polarization-resolved spectroscopy techniques, spanning more than three orders of magnitude in frequency from 100 GHz up to 300 THz. The effect of the size, shape and orientation of the nanostructures is characterized by polarization-sensitive response and modeled by a Maxwell-Garnett effective medium theory.