Growth and Predictive Modeling of InSb Nanopillars by Catalyst-Free Selective Area Epitaxy

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

Technical Description: This project offers a new epitaxial growth approach for a historically difficult material system, InSb. Indium antimonide has attractive properties in several advanced technology applications such as mid-wavelength infrared sensing, ultra-high-speed electronics and thermoelectrics, but it has reached a plateau in evolution because of a lack of semi-insulating, lattice-matched substrates, and generally complex epitaxial requirements. The approach used in this project involves two innovative components to address the limitations of traditional InSb epitaxy: catalyst-free semiconductor InSb nanopillar epitaxy and multi-scale epitaxial modeling of nanopillar formation. Efforts in growth involve control of three-dimensional growth, dopant incorporation, defect formation, and surface passivation in catalyst-free InSb nanopillars by selective-area epitaxy metal-organic chemical vapor deposition. Epitaxial modeling is accomplished using first-principles electronic-structure calculations and atomistic kinetic-Monte-Carlo simulation to correlate to experimental results for a complete understanding of the detailed process of InSb nanopillar self-assembly and inform future experiments. Non-technical Description: The broader impacts of this project are addressed at several levels, including undergraduate and graduate research experience and community outreach efforts to broaden participation in nanotechnology. Graduate students act as mentors to undergraduate students, providing valuable lab experience and exposure to scientific research, and in turn gain leadership and management skills. The dual-department collaboration (mathematics and electrical engineering) at UCLA will help build stronger relationships between theorists and experimentalists to improve our understanding of nanopillar self-assembly and lead to future projects. The resulting technology of this project will provide the foundation for a new InSb nanomaterial platform where lateral dimensions and site-location are controlled via lithography. These materials will potentially serve as building blocks for mid-wavelength infrared/terahertz optoelectronic devices and ultra-high-speed transistors.