I. S. Virt

Deposition of thin Bi2Te3 and Sb2Te3 films by pulsed laser ablation

Bi2Te3 and Sb2Te3 films were obtained by pulsed laser ablation. The films were deposited in vacuum (1 × 10−5 Torr) on single crystal substrates of Al2O3 (0001), BaF2 (111), and fresh cleavages of KCl or NaCl (001) heated to 453–523 K. The films were 10–1500 nm thick. The structures of the bulk material of targets and films were studied by X-ray diffractometry and transmission high-energy electron diffraction, respectively. Electrical properties of the films were measured in the temperature range of 77–300 K. It is shown that the films possess semiconductor properties. Several activation portions are observed in the temperature dependences of resistivity; the energies of activation portions depend on the film thickness and crystallite size.

Deposition of thin Bi{sub 2}Te{sub 3} and Sb{sub 2}Te{sub 3} films by pulsed laser ablation

Bi2Te3 and Sb2Te3 films were obtained by pulsed laser ablation. The films were deposited in vacuum (1 × 10−5 Torr) on single crystal substrates of Al2O3 (0001), BaF2 (111), and fresh cleavages of KCl or NaCl (001) heated to 453–523 K. The films were 10–1500 nm thick. The structures of the bulk material of targets and films were studied by X-ray diffractometry and transmission high-energy electron diffraction, respectively. Electrical properties of the films were measured in the temperature range of 77–300 K. It is shown that the films possess semiconductor properties. Several activation portions are observed in the temperature dependences of resistivity; the energies of activation portions depend on the film thickness and crystallite size.

Properties of Sb{sub 2}S{sub 3} and Sb{sub 2}Se{sub 3} thin films obtained by pulsed laser ablation

The properties of Sb2S3 and Sb2Se3 thin films of variable thickness deposited onto Al2O3, Si, and KCl substrates are investigated by the method of pulsed laser ablation. The samples are obtained at a substrate temperature of 180°C in a vacuum chamber with a residual pressure of 10−5 Torr. The thickness of the films amounted to 40–1500 nm. The structure of the bulk material of the targets and films is investigated by the methods of X-ray diffraction and transmission high-energy electron diffraction, respectively. The electrical properties of the films are investigated in the temperature range of 253–310 K. It is shown that the films have semiconductor properties. The structural features of the films determine their optical parameters.

Properties of HgCdTe crystals passivated by A2B6 layers

Abstract The effect of A 2 B 6 passivating layers on properties of bulk p-Hg 1− x Cd x Te crystals has been studied. CdTe, ZnTe and CdS layers with 400 nm thickness were grown on the surface of a sample by a pulse laser deposition (PLD) method. The galvanomagnetic and photoelectric properties of the passivated crystals were measured. Accordingly, the layers have only a weak influence on the properties of the crystals. The electrical properties of the related Al–CdTe–Hg 0.8 Cd 0.2 Te and Al–CdS–Hg 0.8 Cd 0.2 Te heterostructures obtained by PLD method have been studied too.

Electrical properties of HgCdTe films obtained by laser deposition

Abstract HgCdTe thin films have been obtained on the Al2O3 surface by the pulse laser deposition method in dynamic vacuum. Films grown at the temperature window of 470–490 K exhibit relatively small electrical resistance. The resistance–temperature characteristics of the films are compared to those of the target and they clearly point to intrinsic and impurity regions. The temperature dependency of the Hall coefficient, the stationary and kinetic photoconductivity of the layers as well as the life time of charge carriers have been studied.

Optical absorption and reflectivity spectra of highly chromium doped CdTe alloy and layer

In the present work, a CdTe alloy doped with a relatively high concentration of chromium (1%), and a CdTe:Cr layer, have been studied. Absorption and reflectivity spectra were measured at room temperature. They indicate the presence of chromium in the divalent state, both in the alloy and in the layer.

CdTe as a passivating layer in CdTe/HgCdTe heterostructures

CdTe/Hg1 − xCdxTe heterostructures are studied. In the structures, CdTe is used as a passivating layer deposited as a polycrystal or single crystal on a single-crystal Hg1 − xCdxTe film. The film and a passivating layer were obtained in a single technological process of molecular beam epitaxy. The structure of passivating layers was studied by reflection high-energy electron diffraction, and the effect of the structure of the passivating layer on the properties of the active layer was studied by X-ray diffractometry. Mechanical properties of heterostructures were studied by the microhardness method. Electrical and photoelectrical parameters of the Hg1 − xCdxTe films are reported.

Growth Mechanisms and Structural Properties of Lead Chalcogenide Films Grown by Pulsed Laser Deposition

Three lead chalcogenide films, PbTe, PbSe, and PbS, with a high structural quality were grown by pulsed lased deposition (PLD). The films were grown on single crystal substrates (Si, KCl, Al2O3) and on Si covered with a Si3N4 buffer layer. The Si3N4 layer latter facilitated the lead chalcogenide layer nucleation during the first growth stages and resulted in a more homogeneous surface morphology and a lower surface roughness. The surface geometry (roughness) of the films grown on Si3N4 was studied by means of the power spectral density analysis. Different growth modes, ranging from plasma plume condensation to bulk diffusion, resulting in observed film morphologies were identified. The investigations were complemented by electrical characterization of the chalcogenide films.

Hybrid disordered blends formed from fullerene porous layers and zinc oxide grown by atomic layer deposition

Thermally evaporated fullerene C60 porous films served as templates for a hybrid (molecular-inorganic) disordered blend formation. C60 films were covered with zinc oxide (ZnO) grown by atomic layer deposition. ZnO filled every pore in the C60 layer which led to the formation of C60–ZnO films with separate and distinguishable phases of C60 and ZnO constituents. Morphological, structural, optical, and electrical properties of the so-obtained films were investigated. Deposition of ZnO polycrystalline films on C60 porous layers resulted in the formation of ZnO with additional structural defects, compared to the films grown on planar substrates, which affected the electrical transport in the ZnO–C60 layers.

Optical properties of ZnCoO layers obtained by PLD method

Abstract Optical properties of the zinc-cobalt oxide (ZnCoO) layers manufactured at different process conditions have been investigated. ZnCoO layers were grown on sapphire and glass substrates by pulsed laser deposition (PLD) technique. The influence of growth conditions as well as post-growth annealing on the films transmission and gap energy was analyzed.