Scintillation Properties of Ga2O3 Crystal

Abstract

Ionizing radiation detectors are used in many kinds of non-destructive investigations. Many of such applications use a scintillation detector which consists of scintillator and photodetector. A scintillator is a type of the luminescent material that converts a high energy ionizing radiation photon/particle to hundreds of visible photons via energy migration from the host matrix to emission centers. Scintillators have been playing an important role in many scientific and industrial fields, including astrophysics, particle physics, medical imaging, security, nuclear plants, and well-logging. Although insulator materials doped with rare-earth or transition metal ions are commonly used in practical applications, semiconductor crystals have also attracted attentions due to their intrinsically high light yield and fast decay time without doping of any emission centers. In this work, optical and scintillation properties of well-known Ga2O3 semiconductor material are investigated. Under UV excitation, photoluminescence (PL) emission peak appeared around 380 nm with the quantum yield of 6%, and fast decay of 8 and 793 ns were observed. In contrast, X-ray induced scintillation spectrum also showed an intense emission band around 380 nm, which of decay curve was reproduced by two exponential decay components with the time constants of 8 and 977 ns. The pulse height spectrum of 137Cs g-rays measured using measured Ga2O3 showed a clear photoabsorption peak with a light yield of 15000 ± 1500 ph/MeV. This high light yield was the highest value among the semiconductor scintillators reported.