Predictive morphology control of hydrogen-terminated silicon nanoparticles

Abstract

Control of the shape and surface termination of semiconductor nanoparticles via control of the fabrication conditions is desirable for many technological applications. We present a theoretical model based on density functional theory first principles thermodynamics for the optimal shape and surface reconstruction of hydrogen-terminated silicon nanoparticles, as a function of nanoparticle size and the temperature and hydrogen partial pressure of the formation conditions. We predict nanoparticle shapes to be dominated by (111) facets under most conditions, with fully octohedral shapes available for higher H 2 chemical potential and (113) and (001) facets appearing as H 2 chemical potential decreases. Comparison to previously published nanoparticle shapes reveals agreement between the observed and predicted nanoparticle shapes for the reported chemical conditions. Control of the hydrogen chemical potential should allow nanoparticles with variable fractions of (100) and (113) surfaces to be created, with potential applications for functionalization or control of optoelectronic properties. Show more