Exploring mass dependence in electron-hole clusters

June 18, 2020

In solid materials, when an electron changes position without another to fill its place, a positively charged 'hole' can appear which is attracted to the original electron. In more complex situations, the process can even result in stable clusters of multiple electrons and holes, whose behaviours all depend on each other. Strangely, the masses of each particle inside a cluster can be different to their masses when they are on their own. However, physicists aren't yet entirely clear how these mass variations can affect the overall properties of clusters in real solids. Through a study published in EPJ B, Alexei Frolov at the University of Western Ontario, Canada, reveals that the behaviour of one type of three-particle cluster displays a distinct relationship with the ratio between the masses of its particles.

Clusters of electrons and holes are already known to affect the absorption of light by semiconductors, which are now key components of many modern technologies. Frolov's research could significantly improve our understanding of these important materials, and it may also enable researchers to better explain smaller details in their optical and infrared spectra. In his study, Frolov considered a cluster containing two electrons with ordinary masses, and one hole which could vary between one and two electron masses. Through his calculations, distinctive behaviours emerged which displayed clear relationships with the ratio between the mass of this heavier hole, and that of each lighter electron.

Frolov based his calculations around the principles of quantum mechanics, which he used to derive a series of formulas to describe the mass dependence of three-particle clusters extremely accurately. He now hopes that these formulas could be modified to describe clusters containing four or more particles with varying masses. If achieved, this would create new opportunities to understand and fine-tune the properties of real semiconductors in future research.
-end-
Reference

A Frolov (2020), Mass-dependencies of the bound state properties for three-body positronium-like exitonic complexes, European Physical Journal B 93:87, DOI: 10.1140/epjb/e2020-10076-7

Springer

Related Electrons Articles from Brightsurf:

One-way street for electrons
An international team of physicists, led by researchers of the Universities of Oldenburg and Bremen, Germany, has recorded an ultrafast film of the directed energy transport between neighbouring molecules in a nanomaterial.

Mystery solved: a 'New Kind of Electrons'
Why do certain materials emit electrons with a very specific energy?

Sticky electrons: When repulsion turns into attraction
Scientists in Vienna explain what happens at a strange 'border line' in materials science: Under certain conditions, materials change from well-known behaviour to different, partly unexplained phenomena.

Self-imaging of a molecule by its own electrons
Researchers at the Max Born Institute (MBI) have shown that high-resolution movies of molecular dynamics can be recorded using electrons ejected from the molecule by an intense laser field.

Electrons in the fast lane
Microscopic structures could further improve perovskite solar cells

Laser takes pictures of electrons in crystals
Microscopes of visible light allow to see tiny objects as living cells and their interior.

Plasma electrons can be used to produce metallic films
Computers, mobile phones and all other electronic devices contain thousands of transistors, linked together by thin films of metal.

Flatter graphene, faster electrons
Scientists from the Swiss Nanoscience Institute and the Department of Physics at the University of Basel developed a technique to flatten corrugations in graphene layers.

Researchers develop one-way street for electrons
The work has shown that these electron ratchets create geometric diodes that operate at room temperature and may unlock unprecedented abilities in the illusive terahertz regime.

Photons and electrons one on one
The dynamics of electrons changes ever so slightly on each interaction with a photon.

Read More: Electrons News and Electrons Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.