Comparative study of Ga, In, and Mg doped ZnO thin-film scintillator with Geiger mode APD

Ga 25, 55, and 552 ppm doped, In 25, 53, and 141 ppm doped, Mg 1, 5, 10, 13 mol% doped ZnO thin film scintillators were grown by the Liquid Phase Epitaxy (LPE) method. Their transmittance, α-ray induced emission spectra were evaluated. The transmittance reached to 80% at wavelength longer than 390 nm for all the crystals. Two emission lines appeared at 390 and 550 nm, due to the free and bound excitons, respectively. Coupled with Multi Pixel Photon Counter (MPPC), the light yield and decay time were evaluated.