Luminescence of PbxCa1-XMoO4 solid solution upon excitation with pulsed picosecond electron beam.

Time-resolved spectra emission spectra in region of 250–850 nm, sub-nanosecond luminescence decay kinetics and temperature dependence of luminescence yield in temperature range of 7–295 K were studied in Pb_xCa_1-xMoO₄ solid solutions upon excitation with pulsed picosecond electron beam. For comparison, decay kinetics under pulsed cathodoluminescence (PCL) and pulsed X-ray excited luminescence were studied. In PCL spectra wide emission band was revealed (FWHM=0.6 eV) with the peak maximum in the region of 514–565 nm, which position nonlinearly shifted depending on x parameter describing amount of Pb cation in the compund. PCL light output strongly depends on temperature and increases by dozens of times when cooling to 7 K. Activation energy of quenching nonlinearly depends also on the x parameter. This broad emission band is due intrinsic emission which arises from radiative decay of excitons self-trapped at the (MoO₄)^2- complexes i.e. self-trapped exciton (STE) luminescence. The features of the electronic structure band determine relaxation processes of electronic excitations resulting in radiative decay STE. Spectral and temporal properties of PCL in PbMoO₄ (x=1) were studied in detail. [ABSTRACT FROM AUTHOR]