FREE-EXCITON STATES IN CRYSTALLINE GATE

Polarized properties of both the singlet and triplet ground exciton st ates in the photoluminescence and transmission spectra of crystalline GaTe are explained based on the possible symmetry properties of the en ergy band edge of GaTe. Some experimental results about excited excito n states in GaTe are presented and discussed. The energy positions of exciton series in GaTe follow the three-dimensional direct allowed Wan nier exciton formula just as in the other III-VI layered compounds of GaSe and InSe. The nonthermalized, ''hot'' nature of excitons inside G aTe under higher optical excitation intensities is also discussed.