Intraband luminescence of CsY under laser and electron excitation

Spectra and kinetics of luminescence for pure and activated Na+ of CsI crystals under excitation by electron high-current accelerator (50 ps, 400 keV, 100 A/cm2) and by KrF and XeF exidimensional lasers (5 ns, 107-108 W/cm2, hνB=4.98 and 3.54 eV, respectively) were measured. Fast component of superfast luminescence (SFL) with τ≤10 ps was observed at excitation by CsI and CsI-Na electron pulses. Activator introduction does not affect SFL intensity. Form of SFL pulse does not depend on temperature within 7-400 K range. SFL spectrum has short-wave edge at 2.5 eV. Spectrum is restricted by EOC spectral sensitivity within long-wave range. The obtained experimental data allow to suggest, that SFL short-wave boundary is caused by radiative transitions between 2p3/2 subband flat peak and 2p1/2 subband bottom with hot hole participation