Fast Neutron Scintillation from Ga₂O₃ Crystals for Radiation Detection

Gallium oxide (Ga₂O₃) is a newly emerged ultrawide bandgap (4.9 eV) semiconductor with many applications in deep UV optoelectronics, extreme condition radiation detection and power switching devices. While Ga₂O₃ can be grown via molecular beam epitaxy, it can also be grown from melt using Bridgman technique, thus lower the cost. The large bulk of Ga₂O₃ crystal is particularly suitable for radiation detection. However, a direct optical observation of fast neutron scintillation from Ga₂O₃ crystal is in short supply.

We report fast neutron scintillation from furnace grown bulk Ga₂O₃ crystal. We conducted our experiment at Los Alamos Neutron Science Center (LANSCE) 4FP60R beamline with neutron energy 1 -- 800 MeV. We used a fiber coupled optical spectrometer to observe scintillation spectrum, and we located a spectral peak at 365 nm wavelength. We used a PI-MAX 4 intensified camera from Princeton Instruments to directly image scintillation photon emission pattern, and we observed bright scintillation images. Comparative calibration showed that the scintillation efficiency was approximately 30,000 photons per MeV. We are conducting further data analysis on neutron energy dependent scintillation efficiency.