Tailoring Exciton Dynamics by Elastic Strain-Gradient in Semiconductors

Tailoring exciton dynamics by elastic strain-gradient in semiconductors.

In purely bent ZnO microwires, the excitons can be effectively driven and concentrated by the elastic strain-gradient towards the tensile outer side of the purely bent wire. Experimental and theoretical approaches are combined to investigate the dynamics of excitons in an inhomogeneous strain field with a uniform elastic strain-gradient. Cathodoluminescence spectroscopy analysis on purely bent ...

Exciton dynamics and annihilation in WS2 2D semiconductors.

We systematically investigate the exciton dynamics in monolayered, bilayered, and trilayered WS2 two-dimensional (2D) crystals by time-resolved photoluminescence (TRPL) spectroscopy. The exciton lifetime when free of exciton annihilation was determined to be 806 ± 37 ps, 401 ± 25 ps, and 332 ± 19 ps for WS2 monolayer, bilayer, and trilayer, respectively. By measuring the fluorescence quantum yi...

Strain Gradient Modulated Exciton Evolution and Emission in ZnO Fibers

One-dimensional semiconductor can undergo large deformation including stretching and bending. This homogeneous strain and strain gradient are an easy and effective way to tune the light emission properties and the performance of piezo-phototronic devices. Here, we report that with large strain gradients from 2.1-3.5% μm-1, free-exciton emission was intensified, and the free-exciton interaction ...

Exciton drift in semiconductors under uniform strain gradients: application to bent ZnO microwires.

Optimizing the electronic structures and carrier dynamics in semiconductors at atomic scale is an essential issue for innovative device applications. Besides the traditional chemical doping and the use of homo/heterostructures, elastic strain has been proposed as a promising possibility. Here, we report on the direct observation of the dynamics of exciton transport in a ZnO microwire under pure...

[Article] Optical polarization grating in semiconductors induced by exciton- polaritons