Intraband luminescence excited in new ways: Low-power x-ray and electron beams

Hot intraband luminescence (IBL) was observed under excitation by high-power (120 keV, 10 A/cm2) pulsed electron beam, low-energy (10 keV) and low-current (2 μA) continuous electron beam as well as pulsed x-rays. Thus, the fundamental possibility of IBL excitation by x-rays was confirmed, and for most studied materials the absence of the dependence of IBL spectral shape on excitation energy was revealed. For the first time, the intraband luminescence was monitored under low-power excitation, which confirmed the absence of a power threshold of its mechanism and completely ruled out the role of excitation density effects in IBL formation. The data obtained allow the prediction that the IBL can be excited by single photons of 511-keV energy, which is required for enhancing scintillation time resolution in TOF-PET.