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Information × Registration Number 0212U005700, 0112U005316 , R & D reports Title Sensors to detect toxic molecules popup.stage_title Head Strelchuk Viktor Vasylyovych, Доктор фізико-математичних наук Registration Date 25-12-2012 Organization Institute of Semiconductor Physics of National Academy of Sciences of Ukrain popup.description2 Sensor InAs/Al(Ga)As/GaAs structures with InAs quantum dots (QDs), grown by molecular-beam epitaxy, were investigated by confocal Raman and photoluminescence (PL) microspectroscopy. The effective resonant exciton transfer by the Ferster mechanism from InAs/Al(Ga)As QD to molecules of cyanine dyes was observed. Interaction between molecules of cyanine dyes with chloroform reduces the efficiency of nonradiative resonant energy transfer. The effect of changes in luminescent properties of InAs QDs close to the molecules of cyanine dyes was observed. The possibility of using this effect to create sensors for molecules of different chemicals was demonstrated. The temperature-dependent photoluminescence spectra of different layers of sensor bilayer InAs/Al(Ga)As/GaAs structures was obtained and analyzed. Reducing the thickness of barrier layer between direct-band and indirect-band QDs is shown to lead low-energy shift of direct-band (indirect-band) InAs QDs PL band up to 20 (80) meV. The change of PL band energy position on the composition and quantum-confinement effect was analyzed. Different behavior of temperature-dependent shift of direct and indirect energy bands of InAs/Al(Ga)As/GaAs was found. Significant increase in intensity of direct-band InAs QDs PL band is shown to be due to increase of resonant exciton tunneling with decrease of barrier separating layer thickness. Confocal micro-Raman spectroscopy was used for nondestructive analysis of structure of heterostructure epitaxial layers by scanning along the structure's growth direction with submicron spatial resolution. Intensity and frequency profiles of resonant phonon bands of different layers of InAs/Al(Ga)As/GaAs heterostructure were obtained. Significant compositional intermixing for two-period A3B5 heterostructures with InAs QDs caused by interdiffusion processes in the nonuniform fields of elastic strains was established. Product Description popup.authors Авраменко Катерина Андріївна Коломис Олександр Федорович Ніколенко Андрій Сергійович Романюк Артем Сергійович popup.nrat_date 2020-04-02 Close