Cadmium telluride nanofilms application in carbon monoxide detection
The research is centered on CdTe nanofilms. The article is aimed at developing innovative primary transducer nanoscale material for semi-conductor sensors, investigating their surface physicochemical properties and evaluation their applicability in carbon monoxide diagnostics. Cadmium telluride nanofilms were obtained by discrete thermal evaporation in vacuum. CdTe nanofilms applicability in gas analysis was investigated. Adsorption properties of the given material for carbon oxide (II) and oxygen were studied by the piezoquartz microweighing. The principles of adsorption, depending on the process conditions and the test sample habitus, were established. Based on the obtained experimental data, CO micro-impurities sensors were developed, the laboratory tests passed successfully.
Adsorption of gases on binary and multicomponent semiconductors of the ZnSe-CdTe system
Adsorption of carbon monoxide(II) and oxygen on powders and nanofilms of solid solutions and binary compounds of the ZnSe-CdTe system was studied volumetrically, and by piezoquartz microweighing and IR spectroscopy of multiple disturbed complete internal reflections. The mechanisms and principles of adsorption were established in dependence on the conditions of the habitus of an experimental sample and the composition of the system’s semiconductors, based on an analysis of IR spectra; the thermodynamic and kinetic characteristics of adsorption; experimental dependences αp = f(T), αT = f(P), and αT = f(t); and the acid-base and other physicochemical characteristics of adsorbents and the electron nature of adsorbate molecules. Conclusions drawn earlier as to the retention of local active centers on the surface of a diamond-like semiconductor (which are responsible for adsorption and catalytic processes) upon a change in the habitus of a sample were confirmed. Certain features in the behavior of solid solutions (ZnSe)x(CdTe)1 − x were revealed alongside commonalities with binary compounds (ZnSe, CdTe), testifying to the presence of critical points on “adsorption characteristics-composition” diagrams. The most active adsorbents (with respect to CO and O2) were discovered on the basis of these diagrams, which were used in creating highly sensitive and selective sensors.
Development of Double-Sided CdTe Strip Detectors for γ-Ray Imaging and Spectroscopy
By reading out both anode and cathode strips, double-sided CdTe strip detectors can achieve a large area and a high position resolution with few readout channels, which makes them very attractive for X-ray and γ-ray imaging and spectroscopy. We have developed double-sided CdTe strip detectors, 1.28 ×1.28 cm2 in size and 0.5 and 2.0 mm in thickness. Both electrodes are divided into 32 orthogonal strips with a pitch of 400 µm. For a detector of 0.5 mm thickness, the energy resolution was measured to be 1.5 keV (FWHM) at 60 keV. For the 2.0-mm-thick detector, an energy resolution of 8.0 keV (FWHM) at 662 keV was obtained using only the anode signal. By combining both the anode and cathode signals, we successfully improved the spectral performance and measured an energy resolution of 5.9 keV (FWHM) at 662 keV.