On Binding Energy of Trions in Bulk Materials

TL;DR

This paper investigates the binding energies of negatively and positively charged trions in bulk semiconductors using a potential model and Faddeev equations, finding that negative trions are bound while positive ones are not.

Contribution

It provides a detailed calculation of trion binding energies in bulk materials and analyzes the formation mechanism, comparing contributions of different physical effects.

Findings

Negative trions are bound and agree with previous studies.

Positive trions are unbound in all considered cases.

The formation mechanism involves mass-polarization and Coulomb repulsion contributions.

Abstract

We study the negatively $T^{-}$ and positively $T^{+}$ charged trions in bulk materials in the effective mass approximation within the framework of a potential model. The binding energies of trions in various semiconductors are calculated by employing Faddeev equation in configuration space. Results of calculations of the binding energies for $T^{-}$ are consistent with previous computational studies and are in reasonable agreement with experimental measurements, while the $T^{+}$ is unbound for all considered cases. The mechanism of formation of the binding energy of trions is analysed by comparing contributions of a mass-polarization term related to kinetic energy operators and a term related to the Coulomb repulsion of identical particles.