High Density Excitation Effect of the Indirect Band Luminescence in Thallous Halides

抄録

A broad band luminescence is observed at the indirect gap region in highly purified TlBr and TlCl crystals under high density excitation. From the analysis of the line shape, power dependence, lifetime and some characteristic features of the luminescence, it is discussed the possibility that the luminescence is associated with an LA-phonon assisted indirect recombination (X₆⁺-R₆^-) of electron-hole liquid (EHL). Equilibrium density, binding energy and other parameters of EHL are estimated and it is presumed that the hole-phonon scattering is dominant in their recombination process.