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.
Surface Processing of CdTe Detectors Using Hydrogen Bromide-Based Etching Solution
Chemical etching of CdTe crystals using hydrogen bromide (HBr)-based etchant was studied and its effectiveness in detector leakage current, gamma radiation detection performance was compared with that of a conventional Br-methanol (BM) etched detector. It was found that effect of surface leakage in total detector leakage current was lower in the HBr-processed detectors, and they also exhibited better radiation detection performances than that of the conventional BM-etched detectors. A slight variation in surface chemical states was found in these differently processed crystals which could be related to the observed differences in detector properties.
Analysis of leakage currents in MOCVD grown GaInAsSb based photodetectors operating at 2 µm
This paper reports the fabrication and characterization of GaInAsSb photodetectors operating at 2 µm. At room temperature, the performance of these photodiodes under reverse bias conditions is limited by the surface leakage. A model has been developed to separate the bulk (diffusion and generation-recombination (g-r)) and the surface leakage contributions toward the total leakage current. By fitting this model to the experimental data, values of material parameters such as minority carrier diffusion length and lifetime have been estimated. The highest R0A of 55 Ω-cm2 has been obtained with a responsivity of 0.44 A/W at 2 µm.