Ultraviolet Luminescence of ZnO Whiskers, Nanowalls, Multipods, and Ceramics as Potential Materials for Fast Scintillators

Abstract

The presented work is dedicated to the study and comparison of scintillating properties of zinc oxide samples prepared in different morphologies: whiskers, nanowalls, multipods, and ceramics. It was shown that total transmittance, photo- and radioluminescence spectra, and radioluminescence kinetics can vary significantly depending on sample structure and preparation conditions. The highest total transmittance was registered for ZnO ceramics (>50% at 0.5 mm thickness). Differences in the transmittance of whiskers, nanowalls, and multipods can be attributed to their shape and thickness which affects the amount of light refraction and scattering. The study of radioluminescence demonstrated that all samples, except undoped ceramics and air annealed whiskers, have predominantly fast luminescence with a decay time <1 ns. High transmittance of ceramics opens the way for their use in the registration of high energy X-ray and gamma radiation, where a large volume of scintillators is required. In cases, where large scintillator thickness is not a necessity, one may prefer to use other ZnO structures, such as ensembles of whiskers and nanowalls. Studies of near-band-edge luminescence components at low temperatures showed that the structure is quite similar in all samples except Ga doped ceramics.

Free-Standing ZnO:Mo Nanorods Exposed to Hydrogen or Oxygen Plasma: Influence on the Intrinsic and Extrinsic Defect States

“…In particular, they are implemented in the engineering of solar cells [ 1 , 2 , 3 , 4 ], optoelectronics, photonics, gas- [ 5 ] and biosensors [ 6 ], and photocatalysis [ 7 ]. Another important application of the ZnO nanostructures is radiation detectors (scintillators) [ 8 , 9 ]. Moreover, they have the strong potential for ultrafast detection in time-of-flight positron emission tomography [ 10 ] due to ultraviolet (UV) exciton emission with the maximum at about 380 nm (3.26 eV) [ 11 , 12 , 13 , 14 , 15 ].…”

Charge traps in Zn- and Mo-based oxide microstructures. The role of Mo

“…Due to excellent physical properties such as wide direct bandgap of 3.37 eV and large excitonic binding energy (60 meV at 300 K) [1] zinc oxide (ZnO) attracts attention for decades. Nowadays the most studied are micro-and nanostructures of ZnO [2,3] due to their application in a wide range of technologies, including solar cells [4][5][6][7], optoelectronics, photonics, gas and bio sensors, photocatalysis and scintillators [8][9][10][11]. Significant drawback of the material is its ageing [12].…”

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].…”