Synchrotron-laser pump-probe luminescence spectroscopy: Correlation of electronic defect states with x-ray absorption in wide-gap solids

The potential for synchrotron–laser pump–probe luminescence measurements to provide a direct link between the chemical/structural properties of light emitting wide band-gap solids and optically active electronic trapping states is evaluated. Initial results are presented that demonstrate the various excitation and relaxation processes involved, whereby the synchrotron pump provides the chemical/structural information, and the laser probes both radiative and non-radiative electronic trapping states. The examples described here demonstrate that the laser probe may quench, be neutral, or enhance the synchrotron-pumped luminescence of the wide band-gap materials boron nitride, SiO2 and Na0.7Ca0.3Al1.3Si2.7O8, respectively. Consideration is given to the potential of the method to provide a general route to the analysis of single components in heterogeneous systems.