Magneto-Optical Absorption in Thallous Iodide of CsCl Structure

Abstract

Magneto-optical absorption due to exciton is investigated for thallous iodide of CsCl structure at low temperatures. By the application of magnetic field appear the absorptions due to 2s and 3s excitons which are not observed in zero magnetic field. One-phonon replicas of zero-phonon excitons are found to grow and exciton polaron pinning effect is observed in high magnetic field. The exciton binding energy is determined as 11±1 meV and its reduced mass as (0.25±0.05)m₀. The dielectric constant effective to the exciton binding and the longitudinal optical phonon energy are estimated to be 17±2 and 11±2 meV, respectively.