Free and bound excitons in silver bromide under hydrostatic pressure

Abstract

Employing resonant Raman and luminescence spectroscopy, various exciton states and phonon modes are studied at low temperature in AgBr under hydrostatic pressure up to 0.7 GPa. The deformation potential for the indirect free exciton gap and mode Grüneisen parameters for various phonons are determined. Excitons bound to neutral donors and isoelectronic iodine are found to essentially derive from L-point valence band states.