B Unal

The effect of humidity on electronic conductivity of an Au/CuO/Cu2O/Cu sandwich structure

In this study it was aimed to research the effect of humidity on the current-voltage characteristics and capacitance of an Au/CuO/Cu2 O/Cu sandwich structure. Cuprous oxide (Cu2 O) and cupric oxide (CuO) layers were grown on a copper sheet. In order to complete the fabrication of the Au/CuO/Cu2 O/Cu sandwich structure a gold metal contact was then applied on the cupric oxide layer under the pressure of 1 × 10-6 Torr. The current-voltage characteristics and effective capacitance of the sandwich structure were measured in various humidity ranges at a temperature 20 °C. It was observed that the electronic conduction and capacitance of the Au/CuO/Cu2 O/Cu structure were strongly dependent on humidity. The effect of humidity in Au/CuO/Cu2 O/Cu was discussed by means of the electric dipole moment of water.

Calculation of Resistivities of Liquid Metals and Alloys by a New Method

Mobility formula recently derived by us has been applied to liquid metals and alloys and detailed resistivity calculations has been carried out for Na metal. ρ versus T curve goes almost parellel with the experimental one.

Green function solution of a second-order partial differential equation and conductivity of thin films

Correct form of the Green function G of the Schrodinger equation is developed for a thin metallic film of thickness d which contains infinitesimally weak volume and surface scatterers. Conductivity σ of the film is obtained from the imaginary part of the self-energy Σ appearing in the average G and increases smoothly with d and that density of states is not staircaselike as contrast to the usual. Examination of σ in terms of d agrees well with the experiment.

Dislocation scattering of electrons in plastically deformed germanium

Using the correlation function variant of linear response theory, we calculated the electron mobility due to charged dislocation lines in Ge as a function of temperature T.

Electron mobility in GaAs due to piezoelectric scattering

Theoretical studies so far on piezoelectric scattering have resulted in a mobility behaviour of mu approximately T-1/2 in which mu continues to fall indefinitely with increasing temperature T. Such a behaviour cannot tell us where this scattering will become unimportant, as might be expected on physical grounds. The correct behaviour should be a falling curve first, followed by a gradually increasing one when the scattering ceases to be effective. In this work, by using the force-force correlation function technique within the linear response formalism, we obtained a mu versus T curve that shows just this behaviour.

The effect of disorder on the electronic states of two-dimensional systems

Under suitable approximations, it is shown that mobility of electrons in two-dimensional systems is always zero for a finite value of disorder, irrespective of the type of scattering potential.

The use of the correlation function technique for the Anderson transition

For a completely disordered lattice, it is found that vanishing mobility is attained at a critical atomic density of rho A1/3 a0=0.2, which agrees adequately with known results.

Determination of thermal annealing effect in intrinsic a-Si:H film

Abstract In this study, the bias annealing effect on the density of state (DOS) in amorphous silicon film on single crystalline of silicon was investigated by means of Au/a-Si:H/c-Si/Al heterostructure. In order to fabricate the structure, at first, a-Si:H film was coated on a single crystalline silicon substrate by means of a dc magnetron sputtering technique and then gold and aluminum metal contacts were applied on the top of a-Si:H and c-Si, respectively. The samples were annealed in the annealing temperature range 110–175°C with the negative end of the applied bias voltage kept at the gold side and the capacitance–voltage characteristics heterostructure was measured. DOS around midgap of the i-region was determined by drive-level capacitance technique and the effect of thermal annealing on the DOS was indicated.

Anderson transition in dilute systems with pure exponential interactions

SummaryAssuming a completely disordered lattice it is shown that all the states are localized when the disorder parameterx=a0/0 reachesthe value 0.31, wherea is the mean atomic separation anda0 is the Bohr radius.

Calculation of mobility in semiconductors due to ionized impurities

Abstract Our recently derived mobility formula has been applied to the calculation of the mobility μ in semiconductors arising from impurities. Comparison of our results with measured μ values shows that they remain close to each other in a wide temperature region.