0000000000778781
AUTHOR
D. Millers
Improving the performance of CdZnTe detectors using infrared stimulation
The influence of monochromatic optical stimulation with wavelengths from 400 nm to 1100 on characteristics of the CdZnTe quasi-hemispherical detectors was studied. It was found that illumination with infrared (IR) light of wavelengths (870–900 nm) close to the absorption edge of the CdZnTe significantly improves the detectors performance at room temperature. Improvement can be achieved with low-intensity IR illumination of about 1–10 µW. The higher intensity illumination leads to degradation of the detector spectrometric characteristics. Infrared radiation penetrates into the detector sensitive volume, change the balance equilibrium between free and trapped carriers, leading to improve char…
Laser-Calorimetric Study of Fundamental Absorption Edge in Pb,La(ZrTi)O3 (PLZT) Perovskite Ceramics
The values of the light absorption coefficient of PLZT 10/65/35 ceramics at selected wavelengths have been obtained by laser calorimetric measurements. The absorption coefficient of the PLZT ceramics is an exponential function of the photon energy. Two values of characteristic Urbach energy have been found ΔE1 = 106 meV and ΔE2 = 238 meV. The first one is a characteristic of the potential of electron-phonon interaction of the optically excited transitions from the valence band to the conduction band and does not depend on lattice defects or admixtures. The other characterises the electron-phonon interaction at optical transitions between two localized electron states in the energy gap separ…
Near-band luminescence of CdZnTe detector crystals
The near-band luminescence due to both neutral donor and neutral acceptor bound excitons (D0 Ex), (A0Ex) and its phonon replicas as well as luminescence of donor-acceptor pair (DAP) and deep energy level due to undefined defect state (A band) were studied in CZT detector crystals. The near-band luminescence correlation with detector characteristics was analyzed and the results could be applied for nondestructive detector material selection. It is obtained that some parameters such as a presence and intensity of A and DAP luminescence bands, the decay kinetics in A0Ex-1LO and DAP luminescence bands, are most important characteristics for detector material characterization.
Time-Resolved Luminescence of Nanocrystalline Inorganic Complex Oxides
Two types of complex nanosized oxides – cerium doped Y3Al5O12 (YAG) and CaWO4– have been studied by means of time-resolved luminescence spectroscopy. Comparative study of time-resolve luminescence characteristics of cerium doped YAG single crystal, nanopowders and nanoceramic as well as for CaWO4 macro- and nanocrystals has been done. Two components in the decay kinetic of Ce3+ related emission in YAG nanocrystals were detected and it was suggested that a different energy transfer rate to volume and surface Ce3+ ions takes place. It is shown that the segregation of Ce3+ ions near nanoparticles surface and/or dislocation lines plays a crucial role in degradation of light yield of cerium rela…
Improving the Performance of Quasi-Hemispherical CdZnTe Detectors Using Infrared Stimulation
The influence of monochromatic optical stimulation with wavelengths from 400 to 1100 nm on the characteristics of CdZnTe quasi-hemispherical detectors was studied. It was found that illumination with infrared (IR) light with wavelengths of 870-900 nm close to the absorption edge of the CdZnTe significantly improves the performance of the detector at room temperature. Improvement can be achieved with low-intensity IR illumination at 1-300 μW depending on the chosen wavelength of illumination. Higher intensity illumination was observed to lead to the degradation of the detector's spectrometric characteristics. IR radiation was noted to influence the detector's sensitivity, changing the equili…
Investigation of the influence of light illumination on the characteristics of CdZnTe detectors
The spectral response of optical transmittance, spectrometry characteristics, output signal shapes and leakage currents of CdZnTe detectors with plane parallel electrodes under illumination with light within wavelength region of 400 – 1100 nm are presented.