Role of strain in interacting silicon nanoclusters

TL;DR

This study uses ab-initio calculations to show how strain from embedding matrices and NC-NC forces significantly influences the optical and electronic interactions between silicon nanoclusters, opening pathways for strain-controlled nanophotonic applications.

Contribution

It reveals the fundamental role of strain in modulating orbital localization and transition probabilities in silicon nanocluster pairs, a novel insight for nanophotonics.

Findings

Strain affects orbital localization in Si-NC pairs.

Strain influences transition probabilities between energy states.

Structural strain can enable strain-controlled responses in Si-NC ensembles.

Abstract

The possibility of controlling the optical transition probability between neighbouring silicon nanoclusters (Si-NCs) constitutes nowadays an attractive prospect in nanophotonics and photovoltaics. In this work, by means of theoretical ab-initio calculations we investigate the effect of strain on the opto-electronic properties of Si-NCs pairs. We consider two sources of strain: the strain induced by an embedding SiO2 matrix, and the strain generated by mutual NC-NC forces occurring at small distances. Independently on its source, we observe a fundamental impact of the strain on the orbitals localization and, as a consequence, on the transition probability between energy states, belonging or not to the same NC. The resulting picture allots to the structural strain a fundamental role in the NC-NC interaction mechanisms, suggesting the possibility of enabling a strain-controlled response in Si-NC ensambles.