Nanofocusing, shadowing, and electron mean free path in the photoemission from aerosol droplets

TL;DR

This paper demonstrates the use of angle-resolved photoelectron spectroscopy on aerosol droplets to measure electron mean free paths in liquids, providing new experimental data and a method to optimize image information content.

Contribution

It presents the first angle-resolved photoelectron images of droplets with defined sizes and introduces an approach to optimize photoelectron image information through varying conditions.

Findings

First photoelectron images of water, glycerol, and dioctyl phthalate droplets.

Data on electron mean free paths in liquid water at low kinetic energies.

Method to vary from shadowing to nanofocusing to enhance image information.

Abstract

Angle-resolved photoelectron spectroscopy of aerosol droplets is a promising method for the determination of electron mean free paths in liquids. It is particularly attractive for volatile liquids, such as water. Here we report the first angle-resolved photoelectron images of droplets with defined sizes, viz. of water, glycerol, and dioctyl phthalate droplets. Example simulations of water droplet photoelectron images and data for electron mean free paths for liquid water at low kinetic energy (< 3eV) are provided. We present an approach that allows one to gradually vary the conditions from shadowing to nanofocusing to optimize the information content contained in the photoelectron images.