Radiative decay and phonon scattering of biexcitons in CuCl

Abstract

We have studied the spectra and the temporal behavior of the emissions from biexcitons in CuCl at 4--65 K created via two-photon absorption under weak-excitation conditions using high-repetition-rate (82-MHz) picosecond tunable uv light. Temperature dependences of the interband- and the intraband-relaxation rate of the biexciton are obtained. These relaxations are ascribed to radiative decay to excitons and to single-acoustic-phonon scattering, respectively. It is found that the radiative lifetime of the biexciton is short, 50 ps, and its deformation potential is small, 0.72 eV.