Scintillation properties are often studied by photo-luminescence (PL) and
scintillation measurements. In this work, we combine X-ray-induced luminescence
(XRIL) spectroscopy [Review of Scientific Instruments 83, 103112 (2012)] with PL
and standard scintillation measurements to give insight into the scintillation
properties of un-doped ZnO single crystals. XRIL revealed that ZnO luminescence
proportionally increases with X-ray power and exhibits excellent linearity -
indicating the possibility of developing radiation detectors with good energy
resolution. By coupling ZnO crystals to fast photomultiplier tubes and
monitoring the anode signal, rise times as fast as 0.9 ns were measured.