Structural, optical, and luminescence properties of ZnO:Ga optical scintillation ceramic

Abstract

This paper discusses the characteristics of ZnO and ZnO:Ga ceramics fabricated by uniaxial hot pressing. The short-wavelength transmission limit of zinc oxide ceramics is in the 370-nm region; the long-wavelength limit is determined by the free-charge-carrier concentration and lies in the interval from 5 to 9 μm. The total transmittance of such ceramics in the visible and near-IR regions is about 70% when the sample is 0.5 mm thick. The luminescence spectrum is represented by a broad emission band with maximum at 580 nm, having a defect nature. The introduction of 0.03-0.1 mass % gallium into the zinc oxide structure inhibits grain growth and increases the free-charge-carrier concentration to 3.44 × 10 19 cm −3. As the gallium concentration increases in the range 0.05-0.1 mass % in a ceramic of composition ZnO:Ga, the defect luminescence band is suppressed and a characteristic exciton luminescence is formed with a maximum corresponding to 389 nm and a damping time constant of 1.1 ns.

Scintillation Properties of Li-doped ZnO Translucent Ceramic

“…Judging from the emission peak positions, the emission peaks were due to lattice defects. (15) For the annealed samples, the excitation and emission peaks were at slightly longer and shorter wavelengths than those of the as-prepared sample, respectively. The QYs of the 700 and 800 °C samples were 4.2 and 5.4%, respectively, and the QY of the as-prepared sample was below the detection limit (1%) of the instrument.…”

“…These values were in approximate agreement with thoes in previous reports. (15) The decay curve was composed of three components corresponding to the different types of lattice defect. (15) However, the specific types of lattice defect corresponding to the three components were unclear because several types of lattice defect have similar emission wavelengths according to previous studies.…”

“…(15) The decay curve was composed of three components corresponding to the different types of lattice defect. (15) However, the specific types of lattice defect corresponding to the three components were unclear because several types of lattice defect have similar emission wavelengths according to previous studies. (16,34) X-ray-induced scintillation spectra of the samples are illustrated in Fig.…”

“…ZnO has mostly been studied for its use in semiconductor devices such as LEDs, (12) although other phosphor applications, including scintillators, are expected, similarly to other semiconductor materials such as GaN (13) and Ga 2 O 3 . (14) In terms of its scintillation properties, ZnO shows two types of luminescence: sub-nanosecond luminescence due to free excitons at around 390 nm (15) and microsecond-order luminescence due to lattice defects in the visible region. (16) Some researchers have explored luminescence due to free excitons and reported a scintillation light yield (LY) of In-doped ZnO thin film of 625 ph/5.5 MeV-α.…”

ZnO – Yb2O3 composite optical ceramics: Synthesis, structure and spectral-luminescent properties

“…Uniaxial HPing was successfully applied for fabrication of transparent ZnO ceramics with fascinating scintillating properties [7,10]. Undoped ZnO [7,10], ZnO:Zn [11], ZnO:Ga [10,[12][13][14][15][16] and ZnO:In ceramics as scintillating materials have been developed so far [14,17].…”