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Information × Registration Number 0225U001639, (0121U110388) , R & D reports Title Physical properties of multi-valley semiconductors and LED structures in radiation, thermal, and deformation fields popup.stage_title Дослідження електрофізичних властивостей компенсованих кристалів n-Ge. Вивчення особливостей видимої люмінесценції cвітлодіодів ультрафіолетового випромінювання на основі твердих розчинів нітриду індію-галію. Head Haidar Halyna P., Доктор фізико-математичних наук Registration Date 04-02-2025 Organization Institute of Nuclear Research of the National Academy of Sciences of Ukraine popup.description1 Establishing regularities of changes in the physical properties of multi-valley semiconductors (silicon, germanium), binary and three-component semiconductor LED structures in radiation, thermal, and deformation fields. popup.description2  It was stated that irradiation of InGaN LEDs with 2 MeV electrons leads to an increase in the differential resistance, grows in the barrier potential and a decrease in the carrier concentration in quantum wells. Areas of negative differential resistance were found on the current-voltage characteristics in the temperature range from 77 to 150 K, as well as a fine structure of the emission spectra. In the emission spectra at liquid nitrogen temperature, along with the main band with a wavelength at a maximum of 505 nm, an additional band with a wavelength at a maximum of 525 nm appears, associated with the quantization of the energy levels of quantum wells. In the temperature range close to room temperature, there is a doublet structure of the recombination emission maximum, caused by the formation of phonon repetition of the main emission line. In the range of currents from 1 to 20 mA, a “blue shift” of the main emission line of 7.2 nm occurs, caused by the quantization of the energy states of the nanoscale system. A sharp drop in the quantum yield after a current of 5 mA is caused by the overflow of quantum wells and the increase of quasi-ballistic transfer of non-thermalized carriers above them. Methods for low-temperature measurements of spectral, electrophysical (current-voltage) and operational (quantum yield) characteristics of LEDs have been developed and improved. The technology of irradiation with electrons (Ee = 2 MeV), gamma-quanta of 60Co and 137Cs has been proposed and tested. It has been found that GaAsP is significantly more radiation-resistant than their GaP analogues. Anisotropy of the field dependences of galvanomagnetic effects in uncompensated p-Ge crystals of various crystallographic orientations was revealed, both under the influence of deformation and without it. It was established that isoenergetic surfaces arising as a result of directed deformation cannot be considered the perfect ellipsoids of rotation in the pressure range up to 1 GPa. Product Description popup.authors Yermolchyk Volodymyr O. Varnina Valentyna I. Vorobiov Volodymyr H. Lytovchenko Petro H. Makukha Oleksandr M. Malyi Yevhen V. Pinkovska Myroslava B. Petrenko Ihor V. Starchyk Marharyta I. Tartachyk Volodymyr P. popup.nrat_date 2025-02-04 Close