38 research outputs found
Structural And Optical Properties Of n-Type and p-Type GaAs(1βx)Bix Thin Films Grown By Molecular Beam Epitaxy On (311)B GaAs Substrates
In this paper, we report on the structural and optical properties of n-type Si-doped and p-type Be-doped GaAs(1βx)Bix thin films grown by molecular beam epitaxy on (311)B GaAs substrates with nominal Bi content x=5.4%. Similar samples without Bi were also grown for comparison purposes (n-type GaAs and p-type GaAs). X-ray diffraction, micro-Raman at room temperature, and photoluminescence (PL) measurements as a function of temperature and laser excitation power (PEXC) were performed to investigate their structural and optical properties. X-ray diffraction results revealed that the Bi incorporation in both n-type and p-type doped GaAsBi was similar, despite that the samples present remarkable differences in the number of Bi related defects, non-radiative centers and alloy disorder. Particularly, our results evidence that the Bi-related defects in n- and p-doped GaAsBi alloys have important impact on the differences of their optical properties
Investigation of the Effect of Substrate Orientation on the Structural, Electrical and Optical Properties of n-type GaAs1-xBix Layers Grown by Molecular Beam Epitaxy
Current-Voltage (I-V), Capacitance-Voltage (C-V), Deep Level Transient Spectroscopy (DLTS), Laplace DLTS, Photoluminescence (PL) and Micro-Raman techniques have been employed to investigate the effect of the orientation of the substrates on the structural, electrically and optically active defects in dilute GaAs1βxBix epilayers structures having a Bi composition x = ~5.4%, grown by Molecular Beam Epitaxy (MBE) on (100) and (311)B GaAs planes. X-ray diffraction results revealed that the in-plane strain in the Ga(As,Bi) layer of the samples grown on (100)-oriented substrate (β0.0484) is significantly larger than that of the samples grown on (311)B-oriented substrate. The substrate orientation is found to have a noticeable impact on the Bi incorporation and the electrical properties of dilute GaAsBi Schottky diodes. The I-V characteristics showed that (100) Schottky diodes exhibited a larger ideality factor and higher barrier height compared with (311)B samples. The DLTS measurements showed that the number of electrically active traps were different for the two GaAs substrate orientations. In particular, three and two electron traps are detected in samples grown on (100) and (311)B GaAs substrates, respectively, with activation energies ranging from 0.12 to 0.41 eV. Additionally, one hole trap was observed only in sample grown on (100) substrates with activation energy 0.24 eV. The observed traps with small activation energies are attributed to Bi pair defects. The photoluminescence (PL) and Raman spectra have evidenced different compressive strain which affects considerably the optical properties. Furthermore, the PL spectra were also affected by different contributions of Bi- related traps which are different for different substrate orientation in agreement with DLTS results
Model of the Method of Autonomous Navigation of Unmanned Aerial Vehicles Based on Infrared Images of the Terrain
Π ΡΡΠ°ΡΡΠ΅ ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½Π° ΠΎΠΏΠΈΡΠ°ΡΠ΅Π»ΡΠ½Π°Ρ ΠΌΠΎΠ΄Π΅Π»Ρ Π°Π²ΡΠΎΠ½ΠΎΠΌΠ½ΠΎΠΉ Π½Π°Π²ΠΈΠ³Π°ΡΠΈΠΈ Π±Π΅ΡΠΏΠΈΠ»ΠΎΡΠ½ΡΡ
Π»Π΅ΡΠ°Π»ΡΠ½ΡΡ
Π°ΠΏΠΏΠ°ΡΠ°ΡΠΎΠ² ΠΏΠΎ ΠΈΠ½ΡΡΠ°ΠΊΡΠ°ΡΠ½ΡΠΌ ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΡΠΌ. Π Π°ΡΡΠΌΠΎΡΡΠ΅Π½ ΡΠΏΠΎΡΠΎΠ± ΠΈ Π°Π»Π³ΠΎΡΠΈΡΠΌ
ΡΠ΅Π°Π»ΠΈΠ·Π°ΡΠΈΠΈ ΠΌΠΎΠ΄Π΅Π»ΠΈ Π°Π²ΡΠΎΠ½ΠΎΠΌΠ½ΠΎΠΉ Π½Π°Π²ΠΈΠ³Π°ΡΠΈΠΈ. ΠΠΎΠ»ΡΡΠ΅Π½Ρ ΡΠΈΡΠ»Π΅Π½Π½ΡΠ΅ ΠΎΡΠ΅Π½ΠΊΠΈ ΡΡΡΠ΅ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ
Π°Π²ΡΠΎΠ½ΠΎΠΌΠ½ΠΎΠΉ Π½Π°Π²ΠΈΠ³Π°ΡΠΈΠΈ ΠΏΠΎ Π΄Π°Π½Π½ΡΠΌ ΠΌΠ½ΠΎΠ³ΠΎΡΠΏΠ΅ΠΊΡΡΠ°Π»ΡΠ½ΠΎΠΉ ΡΠ°Π·Π½ΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠΉ ΡΠΎΡΠΎΠ³ΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΎΠΉ
ΡΡΠ΅ΠΌΠΊΠΈ Π·Π΅ΠΌΠ½ΠΎΠΉ ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠΈThe article presents a descriptive model of autonomous navigation of unmanned aerial vehicles based on infrared images. The method and algorithm for implementing the autonomous navigation model are considered. Numerical estimates of the efficiency of autonomous navigation based on multispectral multi-time photographic survey of the Earth's surface are obtaine
Modeling of the Optimal Flight Route of Unmanned Aerial Vehicles Based on Infrared Video Navigation Data Based on the Upgraded Dijkstra Algorithm
Π ΡΡΠ°ΡΡΠ΅ ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½Π° ΠΌΠΎΠ΄Π΅Π»Ρ ΠΏΠΎΡΡΡΠΎΠ΅Π½ΠΈΡ ΠΎΠΏΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠ³ΠΎ ΠΌΠ°ΡΡΡΡΡΠ° ΠΏΠΎΠ»Π΅ΡΠ°
Π±Π΅ΡΠΏΠΈΠ»ΠΎΡΠ½ΡΡ
Π»Π΅ΡΠ°ΡΠ΅Π»ΡΠ½ΡΡ
Π°ΠΏΠΏΠ°ΡΠ°ΡΠΎΠ² ΠΏΠΎ Π΄Π°Π½Π½ΡΠΌ ΠΈΠ½ΡΡΠ°ΠΊΡΠ°ΡΠ½ΠΎΠΉ Π²ΠΈΠ΄Π΅ΠΎΠ½Π°Π²ΠΈΠ³Π°ΡΠΈΠΈ Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅
ΠΌΠΎΠ΄Π΅ΡΠ½ΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ Π°Π»Π³ΠΎΡΠΈΡΠΌΠ° ΠΠ΅ΠΉΠΊΡΡΡΡ. Π Π°ΡΡΠΌΠΎΡΡΠ΅Π½ ΡΠΏΠΎΡΠΎΠ± ΠΈ Π°Π»Π³ΠΎΡΠΈΡΠΌ ΡΠ΅Π°Π»ΠΈΠ·Π°ΡΠΈΠΈ ΠΌΠΎΠ΄Π΅Π»ΠΈ
ΠΏΠΎΡΡΡΠΎΠ΅Π½ΠΈΡ ΠΎΠΏΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠ³ΠΎ ΠΌΠ°ΡΡΡΡΡΠ° ΠΏΠΎΠ»Π΅ΡΠ°. ΠΠΎΠ»ΡΡΠ΅Π½Ρ ΡΠΈΡΠ»Π΅Π½Π½ΡΠ΅ ΠΎΡΠ΅Π½ΠΊΠΈ ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ
ΡΠ°ΡΡΠΎΡΡ Π·Π½Π°ΡΠ΅Π½ΠΈΠΉ ΠΊΠΎΡΡΠ΅Π»ΡΡΠΈΠΈ ΠΌΠ΅ΠΆΠ΄Ρ ΠΎΠΏΠΎΡΠ½ΡΠΌΠΈ (ΡΡΠ°Π»ΠΎΠ½Π½ΡΠΌΠΈ) ΠΈ ΡΠ΅ΠΊΡΡΠΈΠΌΠΈ ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΡΠΌΠΈ
Π² ΠΈΠ½ΡΡΠ°ΠΊΡΠ°ΡΠ½ΠΎΠΌ Π΄ΠΈΠ°ΠΏΠ°Π·ΠΎΠ½Π΅ Π΄Π»ΠΈΠ½ Π²ΠΎΠ»Π½ Π² ΡΠ°Π·Π½ΠΎΠ΅ Π²ΡΠ΅ΠΌΡ ΡΡΡΠΎΠΊ. ΠΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ Π°ΠΊΡΡΠ°Π»ΡΠ½ΡΠΉ ΠΏΠ΅ΡΠΈΠΎΠ΄
Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ ΡΡΡΠΎΠΊ Π΄Π»Ρ ΡΠΎΠ·Π΄Π°Π½ΠΈΡ ΠΈ Π΄Π°Π»ΡΠ½Π΅ΠΉΡΠ΅Π³ΠΎ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΡ ΠΎΠΏΠΎΡΠ½ΡΡ
(ΡΡΠ°Π»ΠΎΠ½Π½ΡΡ
) ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΠΉ
Ρ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΠΎ Π΄Π»ΠΈΡΠ΅Π»ΡΠ½ΡΠΌ Π²ΡΠ΅ΠΌΠ΅Π½Π΅ΠΌ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΡ Π² ΡΠ΅ΡΠ΅Π½ΠΈΠ΅ ΡΠ»Π΅Π΄ΡΡΡΠΈΡ
ΡΡΡΠΎΠΊ. ΠΠΎΡΡΡΠΎΠ΅Π½Ρ
ΠΎΠΏΡΠΈΠΌΠ°Π»ΡΠ½ΡΠ΅ ΠΌΠ°ΡΡΡΡΡΡ Ρ ΠΊΠΎΠΎΡΠ΄ΠΈΠ½Π°ΡΠ°ΠΌΠΈ ΠΎΠΏΠΎΡΠ½ΠΎΠ³ΠΎ (ΡΡΠ°Π»ΠΎΠ½Π½ΠΎΠ³ΠΎ) ΠΌΠ°ΡΡΡΡΡΠ° ΠΎΡΠ½ΠΎΡΠΈΡΠ΅Π»ΡΠ½ΠΎ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ
ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΎΠΏΠΎΡΠ½ΠΎΠ³ΠΎ ΠΌΠ°ΡΡΡΡΡΠ° Ρ ΡΡΠ΅ΡΠΎΠΌ ΡΠ°ΡΠΏΠΎΠ·Π½Π°Π²Π°Π½ΠΈΡ Π·ΠΎΠ½ Π±Π»ΠΎΠΊΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΏΠΎΠ»Π΅ΡΠΎΠ² Π±Π΅ΡΠΏΠΈΠ»ΠΎΡΠ½ΡΡ
Π»Π΅ΡΠ°ΡΠ΅Π»ΡΠ½ΡΡ
Π°ΠΏΠΏΠ°ΡΠ°ΡΠΎΠ² ΠΏΠΎ Π°Π»Π³ΠΎΡΠΈΡΠΌΡ ΠΠ΅ΠΉΠΊΡΡΡΡThe article presents a model for constructing the optimal flight route of unmanned aerial vehicles based on infrared video navigation data based on the upgraded Dijkstra algorithm. The method and algorithm for implementing the model for constructing the optimal flight route are considered. Numerical estimates of the frequency distribution of correlation values between reference (reference) and current images in the infrared wavelength range at different times of the day are obtained. The actual time period of the day is determined for the creation and further use of reference (reference) images with the longest possible use time during the next day. Optimal routes are constructed with the coordinates of the reference (reference) route, relative to the time of the formation of the reference route, taking into account the recognition of the zones of blocking flights of unmanned aerial vehicles according to the Dijkstra algorith
Model for Calculating the Thermophysical Characteristics of Materials According to Multispectral Multi-Temporal Photographic Survey of the Earthβs Surface
Π ΡΡΠ°ΡΡΠ΅ ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½Π° ΠΌΠΎΠ΄Π΅Π»Ρ ΡΠ°ΡΡΠ΅ΡΠ° ΡΠ΅ΠΏΠ»ΠΎΡΠΈΠ·ΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΎΠ² ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»ΠΎΠ²
ΠΏΠΎ Π΄Π°Π½Π½ΡΠΌ ΠΌΠ½ΠΎΠ³ΠΎΡΠΏΠ΅ΠΊΡΡΠ°Π»ΡΠ½ΠΎΠΉ ΡΠ°Π·Π½ΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠΉ ΡΠΎΡΠΎΠ³ΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΡΠ΅ΠΌΠΊΠΈ Π·Π΅ΠΌΠ½ΠΎΠΉ ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠΈ.
ΠΡΠΎΠ²Π΅Π΄Π΅Π½ Π°Π½Π°Π»ΠΈΠ· ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΡ Π΄Π°Π½Π½ΡΡ
ΡΠ΅ΠΏΠ»ΠΎΡΠΈΠ·ΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΎΠ² ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»ΠΎΠ² Π΄Π»Ρ
ΠΈΠ΄Π΅Π½ΡΠΈΡΠΈΠΊΠ°ΡΠΈΠΈ ΠΎΠ±ΡΠ΅ΠΊΡΠΎΠ² ΠΌΠΎΠ½ΠΈΡΠΎΡΠΈΠ½Π³Π°; ΠΏΠΎΠ»ΡΡΠ΅Π½Ρ ΡΠΈΡΠ»Π΅Π½Π½ΡΠ΅ ΠΎΡΠ΅Π½ΠΊΠΈ ΠΏΠΎΠ³ΡΠ΅ΡΠ½ΠΎΡΡΠΈ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ
ΡΠ΅ΠΏΠ»ΠΎΡΠΈΠ·ΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΎΠ² ΠΈΡΠΏΡΡΡΠ΅ΠΌΡΡ
ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»ΠΎΠ², Π³ΠΈΡΡΠΎΠ³ΡΠ°ΠΌΠΌΡ ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ
ΡΠ΅ΠΏΠ»ΠΎΡΠΈΠ·ΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΎΠ² ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»ΠΎΠ² ΠΏΠΎ Π΄Π°Π½Π½ΡΠΌ Π½Π°ΡΡΡΠ½ΠΎΠ³ΠΎ ΡΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°The article presents a model for calculating the thermophysical parameters of materials according to multispectral multi-temporal photographic survey of the Earthβs surface. The analysis of using data on the thermophysical parameters of materials for the identification of monitoring objects is carried out. The numerical estimates of the errors in determining the thermophysical parameters of the tested materials and distribution histograms of the thermophysical parameters of materials according to the field experimental data are also obtaine