Growth and properties of new ZnSe(Al,O,Te) semiconductor scintillator

Abstract

The zinc selenide crystals were grown in graphite crucibles by Bridgman-Stockbarger method in vertical compression furnace under argon pressure of 5 x 10(6) Pa. The grown ZnSe(Al,O,Te) single crystals were annealed in a Zn vapor at 1290K for 24h. An X-ray diffractometer (XRD) was used to investigate the structural properties of the zinc selenide single crystals. The lattice constants of the ZnSe single crystals were obtained from XRD data. After annealing it in a Zn vapor at 1290 K, it is found that the lattice constant decreases. From the absorption spectra, the band gap energies of the ZnSe single crystals were calculated by a linear fitting process. The band gap energy of the ZnSe(Al,O,Te) single crystal decreases more than that of the ZnSe single crystal. The maximum wavelength of the radioluminescence of the ZnSe(Al,O,Te) scintillator excited by X-ray was 606 nm, which was well matched with the response wavelength of the Si photodiode. The energy resolution of the annealed ZnSe(Al,O,Te) scintillator was 13.9% when it was exposed to (CS)-C-137 gamma-ray. Its size was 10 x 10 x 1 mm(3). The afterglow level of the annealed ZnSe(Al,O,Te) scintillator after 5 ms was 0.014%. The luminescence decay time of the annealed ZnSe(Al,O,Te) scintillator has two exponential components with 4 and 12 mu s time constants. The charged particle and the low energy gamma ray can be detected successfully with the annealed ZnSe(Al,O,Te) scintillator. It was investigated that the ZnSe(Al,O,Te) scintillator can be used for the security inspection system.