Linear, diatomic crystal: single-electron states and large-radius excitons

TL;DR

This paper investigates the electronic and excitonic properties of a linear diatomic crystal, revealing that the exciton binding energies exceed the band gaps, using a zero-range potential approach.

Contribution

It introduces a method to compute the large-radius exciton spectrum in a diatomic linear crystal based on single-electron eigenfunctions and band structure.

Findings

Exciton binding energies are larger than the energy gaps in the crystal.

The study uses the zero-range potential method for calculations.

Results suggest strong excitonic effects in the crystal.

Abstract

The large-radius exciton spectrum in a linear crystal with two atoms in the unit cell was obtained using the single-electron eigenfunctions and the band structure, which were found by the zero-range potential (ZRP) method. The ground-state exciton binding energies for the crystal in vacuum appeared to be larger than the corresponding energy gaps for any set of the crystal parameters.