Measurement of light diffusion in ZnO nanowire forests

TL;DR

This paper demonstrates a novel optical method to measure light diffusion in ZnO nanowire forests, providing insights crucial for optimizing nanowire solar cell design.

Contribution

It introduces an ultrafast all-optical shutter technique to directly measure light dwell time in nanowire arrays, linking optical properties with SEM image analysis.

Findings

Photon mean free path can be predicted from SEM images.

Dwell time of light correlates with nanowire disorder.

Method enables better understanding of light behavior in nanostructures.

Abstract

Optimum design of efficient nanowire solar cells requires better understanding of light diffusion in a nanowire array. Here we demonstrate that our recently developed ultrafast all-optical shutter can be used to directly measure the dwell time of light in a nanowire array. Our measurements on disordered ZnO nanowire arrays, "nanowire forests," indicate that the photon mean free path and the dwell time of light can be well predicted from SEM images.