Non-resonant X-ray/laser interaction spectroscopy as a method for assessing charge competition, trapping and luminescence efficiency in wide band-gap materials

Using a conventional fast-shuttered laboratory X-ray source in combination with pulsed laser diode modules, the possibilities for undertaking X-ray/laser interaction spectroscopy in wide band-gap luminescent materials are explored. It is shown that in such materials, a variety of X-ray/laser timing sequences can extract complimentary information regarding the charge-carrier trapping, de-trapping and recombination processes. The effects on the luminescence are illustrated for six example materials (YPO₄:Ce,Sm, Lu ₃Al₅O₁₂:Pr, Al₂O₃:C, natural sodium feldspar NaAlSi₃O₈, cubic BN and type IIa natural diamond). By ramping the temperature from 10 to 320 K during repeated X-ray pump/laser-probe activation cycles, a rapid assessment can be made of the important thermally dependent changes to the charge carrier trapping competition processes.