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Gazizov I.M.,JSC Institute in Physical Technical Problems | Kuznetsov M.V.,GIREDMET | Lisitsky I.S.,GIREDMET | Zaletin V.M.,JSC Institute in Physical Technical Problems
IEEE Nuclear Science Symposium Conference Record | Year: 2010

The dark conductivity has been studied on pure and doped TlBr crystals obtained by Bridgement method with different compositions and pressures of the residual vapors over the melt. The specific resistance of the pure crystals at room temperature was (0.7-2) 1010 cm and that of doped crystals depended on the amount of the incorporated Pb impurity and was equal to 1.81011 cm. The conductivity activation energy near room temperature was equal to 0.8-0.85 eV and 0.6-1.2 eV for the pure and doped crystals, respectively. The conductivity activation energy of the studied crystals is in agreements with the known values of the energies of formation and dislocation of Schottky defects in TlBr at high temperatures. The expression for the dependence of the crystal specific resistance on their content of Pb bivalent cations has been found. The equilibrium concentration of Schottky point defects in the studied TlBr pure crystals has been calculated and it was equal to 6.41014 cm3. The displacement mobilities of anionic and cationic vacancies were a 9.8 107 cm2 V 1 c1 and c 3.41010 cm2 V1 c1, respectively. The studies have been carried out within the frame of the ISTC project # 2728. © 2010 IEEE.

Polyakov A.Y.,Giredmet | Markov A.V.,Giredmet | Duhnovsky M.P.,Istok | Mezhennyi M.V.,Giredmet | And 15 more authors.
Journal of Vacuum Science and Technology B:Nanotechnology and Microelectronics | Year: 2010

Growth of GaN on polycrystalline chemical vapor deposition (CVD) diamond prepared on Si was achieved by hydride vapor phase epitaxy (HVPE). If the polycrystalline CVD diamond is separated from the Si substrate and the side turned to Si is covered by either TiN or anodic Al oxide, this is found to facilitate deposition of good crystalline quality GaN films. Porous TiN in these experiments was formed by Ti evaporation and subsequent in situ nitridation in the HVPE reactor during pregrowth heating. The films showed double crystal x-ray (0002) rocking curve half width of 245 in. and a strong bandedge luminescence. Thick films self-separated from the substrate. When growing GaN on the Si side of the diamond substrate is covered with porous Al anodic oxide, the authors observed the formation of well defined (0001) GaN texture with the maximum angle between the c-axes of various grains lower than 6.5°, a very low (120 in.) half-width of the (0002) rocking curves of individual grains and an intense bandedge luminescence. © 2010 American Vacuum Society.

Polyakov A.Y.,Giredmet | Markov A.V.,Giredmet | Mezhennyi M.V.,Giredmet | Donskov A.A.,Giredmet | And 10 more authors.
Journal of Vacuum Science and Technology B:Nanotechnology and Microelectronics | Year: 2010

Thick a-plane GaN films were grown by hydride vapor phase epitaxy on a-plane GaN templates prepared by metalorganic chemical vapor deposition (MOCVD) and also on a-plane MOCVD templates using in situ nitridized Ti underlayers. The growth on a-GaN showed improved crystalline quality with increasing hydride vapor phase epitaxy thickness, while MOCVD template quality had little effect. With 30 nm Ti films deposited on the templates and converted to TiN islands by nitridation during growth, the authors obtained thick (350 μm), freestanding a-GaN films detached from the template. Microcathodoluminescence spectra of the growth surface showed intense band edge luminescence at 3.47 eV at 90 K with no defect bands. Spectra taken from the surface turned to the substrate were dominated by stacking fault-related bands at 3.42, 3.3, and 3.0 eV, similar to the spectra of the a-GaN templates. X-ray measurements showed the freestanding a-GaN layers consisted of misoriented large grains of a-GaN with halfwidth for individual grains close to 300-400 arc sec and halfwidth anisotropy with respect to sample rotation around the [11-20] direction. © 2010 American Vacuum Society.

Boitar K.O.,Moscow Institute of Physics and Technology | Poluneev B.B.,Orion RandP Association | Iakovleva N.I.,Orion RandP Association | Denisov I.A.,GIREDMET | Smirnova N.A.,GIREDMET
Applied Physics | Year: 2011

Performances of the 2×2×288 two-color MCT TDI FPA on the basis of MCT liquid phase heteroepitaxial structures have been investigated. Multilayer heteroepitaxial structure FPA is realized in such manner that the photodiodes of 8-12 pm spectral range are formed in top MCT sensitive layer, the photodiodes of 3-5 μm spectral range are formed into a pocket with 6 μm depth. The difference between photosensitive lines of 8-12 μrn and 3-5 μm spectral ranges is less than 100 μm at 28 μm element-to-element pitch that provides the easy scanner adjustment. Photoelectric performances of the 2×2×288 two-color MCT TDIFPA in 3-5 and 8-12 μm spectral ranges are close to the theoretical limit restricted by a noise of background radiation.

Vtyurina D.N.,RAS Semenov Institute of Chemical Physics | Romanov A.N.,RAS Semenov Institute of Chemical Physics | Kuznetsov M.S.,Giredmet | Fattakhova Z.T.,RAS Semenov Institute of Chemical Physics | And 3 more authors.
Russian Journal of Physical Chemistry B | Year: 2016

IR photoluminescence of bismuth-doped ternary thallium chloride TlCdCl3 was studied. Two bismuth-containing luminescence impurity centers were detected. One of these was found to be the bismuth Bi+ monocation, emitting at 1025 nm. © 2016, Pleiades Publishing, Ltd.

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