Electrical and thermoelectric properties of ZnO under atmospheric and hydrostatic pressure

Deep Donor Levels in Semiconductors with Vacancies in the Anion Sublattice

“…Positions of these levels against the Γ -valley edge of conductivity band and pressure coefficients for these levels have been obtained. Figure 7 demonstrates the ε d = f (ε g ) dependence of the deep donor center energies for arsenic vacancies relative to the conduction band bottom on the band gap widths for InAs, CdSnAs 2 , CdGeAs 2 , GaAs and CdTe [32] and ZnO [33]. In brief, the figure is the main point of the paper.…”

“…The n-type deep centers, for which the energy levels are located under the conductivity band bottom, have been calculated from the experimental baric and temperature dependences of electron transport in the CdTe [32] and n-ZnO [33] undoped bulk single crystals. It was found that ε d = 0.112 eV for n-CdTe, and ε d = 0.37 eV for n-ZnO.…”

Electrical properties of bulk n‐ZnO single crystals under hydrostatic pressure

“…Such a character of R H (P) and ρ(P) dependences is caused by an increase in the ionization energy of a donor, likely an interstitial native defect of the zinc atom [1,7]:…”

“…Nevertheless, data on electron transport phenomena at atmospheric and hydrostatic pressures obtained for bulk crystals are still not sufficient (see [1][2][3][4][5][6] and references therein). Earlier in [7], the kinetic properties of charge carriers in ZnO bulk crystals had been investigated depending on temperature (77-400 K at atmospheric pressure) and hydrostatic pressure up to P = 7 GPa at 300 K. In the present work these investigations are continued, being supplemented with measurements of the resistivity at quasihydrostatic pressure up to P = 25 GPa at T = 300 K.…”

“…In accordance with formulas derived from the 'heterophase structure -effective medium' model, phase volume fractions in the critical region of the polymorphous transformation have been calculated and the threshold values of normalized effective resistivity have been determined. [6] means that this donor center is a hydrogen-like shallow one [7]. According to Eq.…”