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.Comment: 7 pages, 4 figure