Tailoring exciton dynamics by elastic strain-gradient in semiconductors

TL;DR

This paper demonstrates that elastic strain-gradient can be precisely controlled in ZnO nanowires, fundamentally altering exciton dynamics and offering a new method to tailor electronic and optical properties in semiconductors.

Contribution

It introduces a combined experimental and theoretical method to create and manipulate elastic strain-gradients in semiconductors, impacting exciton behavior.

Findings

Elastic strain-gradient can be created controllably and reversibly in ZnO nanowires.

Inhomogeneous strain distribution alters neutral exciton dynamics.

The principles are applicable to a wide range of semiconductors.

Abstract

As device miniaturization approaches the atomic limit, it becomes highly desirable to exploit novel paradigms for tailoring electronic structures and carrier dynamics in materials. Elastic strain can in principle be applied to achieve reversible and fast control of such properties, but it remains a great challenge to create and utilize precisely controlled inhomogeneous deformation in semiconductors. Here, we take a combined experimental and theoretical approach to demonstrate that elastic strain-gradient can be created controllably and reversibly in ZnO micro/nanowires. In particular, we show that the inhomogeneous strain distribution creates an effective field that fundamentally alters the dynamics of the neutral excitons. As the basic principles behind these results are quite generic and applicable to most semiconductors, this work points to a novel route to a wide range of applications in electronics, optoelectronics, and photochemistry.