5 research outputs found
Mechanisms of electron scattering in uniaxially deformed - single crystals
Temperature dependencies for concentration and the Hall mobility of electrons
for the - and \linebreak
- single crystals
uniaxially deformed along the crystallographic directions [100] and [111] are
obtained on the basis of piezo-Hall effect measurements. A deformation-induced
increase of the Hall mobility of electrons for - single crystals at the uniaxial pressure along the
crystallographic direction [100] has been revealed. A comparison of the
obtained experimental results with the corresponding theoretical calculations
of temperature dependencies of the Hall mobility showed that the obtained
effect occurs at the expense of the reduction probability of electron
scattering on the fluctuational potential. Its amplitude depends on the
tempe\-rature and on the value of the uniaxial pressure. It has also been shown
that an increase of the Hall mobility for the - single crystals uniaxially deformed along the
crystallographic direction [111] with an increasing temperature turns out to be
insignificant and is observed only for the uniaxial pressures GPa. A
decrease of the Hall mobility of electrons at the expense of the deformational
redistribution of electrons among the valleys of the germanium conduction band
with different mobility should be taken into account in the present case. The
Hall mobility magnitude for the uniaxially deformed - single crystals is determined only by the mechanisms
of phonon scattering and we have not observed the effect of the growth of the
Hall mobility with an increase of temperature or the magnitude of uniaxial
pressure.Comment: 10 pages, 7 figure
Influence of Uniaxial Elastic Deformation on the Location of Deep Energy Levels EC 0,2 eV in n-Ge<Au> Single Crystals
Досліджено вплив одновісної пружної деформації на величину зміни положення глибокого енергетичного
рівня золота EC 0,2 еВ в n-Ge за даними п’єзоопору у широкій області механічних напруг X = 0 1,2 ГПа для
XJ| | ||[011] та X || J || [100]. Представлено метод розрахунку швидкості зміщення глибоких рівнів і оцінено
ступінь їх заповнення при одновісній деформації. Обчислено величину зміни енергетичної щілини між
глибоким енергетичним рівнем EC 0,2 еВ і долинами зони провідності n-Ge при деформації вздовж
кристалографічних напрямків [110] і [100]. Визначено середнє значення коефіцієнта (ступінь заповнення
глибоких енергетичних рівнів) для різних температур.; The influence of
uniaxial elastic deformation on the change of the location of deep energy level of gold EC 0,2 eV in n-Ge according
to piezoresistance in wide area of mechanical stress X =0-1,2 GPa is investigated under a condition X || J || [110] and
XJ| | ||[001]. The method of calculation of shift rate is represented and the state of filling of the energy levels ( ) to
an uniaxial deformation is estimated. A change of the energy gap between the deep energy level EC 0,2 eV and the
conduction band valleys in n-Ge arising due to deformation along the crystallographic directions [110] and
[0 01] is calculated. The value average of an at different temperatures was determined
Radiation defects parameters determination in n-Ge single crystals irradiated by high-energy electrons
Hall effect for single crystals of n-Ge, irradiated by various streams of electrons with an energy of 10 MeV is investigated. Taking into account the experimental results, the energy spectrum of radiation defects is found and their parameters are established. On the basis of solutions of electroneutrality equations systems, it is shown that the created radiation defects correspond to only two deep energy levels (Ec - 0.27) eV and (Ec + 0.27) eV. A slight change of energy position of these levels with irradiation dose increasing can be explained by internal mechanical stresses influence that arise in the germanium lattice around created radiation defects
Determination of the activation energy of A-center in the uniaxially deformed n-Ge single crystals
Based on the decisions of electroneutrality equation and experimental results of measurements of the piezo-Hall-effect the dependences of activation energy of the deep level A-center depending on the uniaxial pressure along the crystallographic directions [100], [110] and [111] for n-Ge single crystals, irradiated by the electrons with energy 10 MeV are obtained. Using the method of least squares approximational polynomials for the calculation of these dependences are obtained. It is shown that the activation energy of A-center deep level decreases linearly for the entire range of uniaxial pressure along the crystallographic direction [100]. For the cases of uniaxial deformation along the crystallographic directions [110] and [111] decrease of the activation energy according to the linear law is observed only at high uniaxial pressures, when the A-center deep level interacts with the minima of the germanium conduction band, which proved the lower at the deformation. The various dependences of the activation energy of A-center depending on the orientation of the axis of deformation may be connected with features of its microstructure