SCATTERING AND LIFETIME OF HOT EXCITONS INTERACTING WITH LO-PHONONS IN INBR AND INI POLAR SEMICONDUCTORS

Scattering probabilities and lifetime for a ''hot'' Wannier-Mott excit on which interacts with LO-phonons in InBr and InI polar semiconductor s are obtained for T = 0. The calculations were per formed for exciton states with principal quantum number n = 2 in the states l = 1, m = 0 and I = 1, m = +/-1, when electron and hole effective masses are equa l (m(e) = m(h)). The results obtained can be used to explain the speci al characteristic of secondary radiation emission spectrum measured by Yoshida et al. in 1985. In the latter work, the scattering lines show an alterating intensity which can be accounted for only if the electr on and hole effective masses are nearly equal. Ah computation was perf ormed for different scattering probabilities of the excitons, namely: intraband (W-s), inter-exciton band (W2-->1), disintegration into the continuous spectrum (W-d), as well as the lifetime of the exciton in b oth states. The results show that W-s is larger than W2-->1, even in t he case m(e) = m(h), for a wide range of kinetic energy of the exciton s. A comparison of these results with those for the case of excitons i n the state n = 1 is also made.