Optical and scintillation properties of Cd-doped ZnO film

In the present study, we developed high crystalline quality Cd ²⁺-doped ZnO (Cd:ZnO) scintillator by the liquid phase epitaxy (LPE) method to enhance the defect related emission in ZnO for α-ray detectors. In order to imitate the scintillator application, we investigated α-ray induced radio luminescence spectrum and emission bands peaking around 380 and 500nm were observed, and the latter one was largely enhanced when compared with pure ZnO. Then, we optically coupled the sample with PMT R7600 by Silicone grease, and irradiated ²⁴¹Am 5.5MeV α-ray. Cd:ZnO showed about 700% light yield of pure ZnO scintillator and the total light yield turned out to be 18000 photons/5.5MeV-α. The main component of the scintillation decay time constants turned out to be ~1 ns and 2 μs due to the free exciton and the defect related emissions, respectively.