Viscosity, Second pVT-Virial Coefficient, and Diffusion of Pure and Mixed Small Alkanes CH4, C2H6, C3H8, n-C4H10, i-C4H10, n-C5H12, i-C5H12, and C(CH3)4 Calculated by Means of an Isotropic Temperature-Dependent Potential. I. Pure Alkanes

2006 ◽  
Vol 35 (3) ◽  
pp. 1331-1364 ◽  
Author(s):  
L. Zarkova ◽  
U. Hohm ◽  
M. Damyanova

1987 ◽  
Vol 106 ◽  
Author(s):  
Mark S. Rodder ◽  
Dimitri A. Antoniadis

ABSTRACTIt is shown that the grain boundary (GB) in polycrystalline-silicon (poly-Si) films need not be modeled as a temperature-dependent potential barrier or as an amorphous region to explain the temperature (T) dependence of resistivity (ρ) in p-type poly-Si films at low T. Specifically, we consider that QB defect states allow for the tunneling component of current to occur by a two-step process. Incorporation of the two-step process in a numerical calculation of ρ vs. T results in excellent agreement with available data from 100 K to 300 K.



2019 ◽  
Vol 59 (1) ◽  
Author(s):  
Patrik Ščajev ◽  
Liudvikas Subačius ◽  
Kęstutis Jarašiūnas ◽  
Masashi Kato

Carrier dynamics in n-type 4H-SiC epilayers of varying thicknesses and low Z1/2 defect concentrations are investigated here in wide ranges of excess carrier density and temperature. Several techniques are employed to monitor carrier diffusion and recombination processes, including light induced transient grating (LITG), microwave photoconductance decay (MPCD) and free carrier absorption (FCA) using ps-laser pulses at 355 nm. The observed increase of the diffusion coefficient with the increasing excitation level is explained by the transition from the minority to the bipolar transport regime. Its subsequent decrease with even higher excitations is found to be governed by band-gap renormalization and degeneracy effects. The bulk lifetime, limited by hole traps at 0.19–0.24 eV above the valence band at lower excitations, was found to decrease from few microseconds to hundreds of nanoseconds during the transition regime from the minority to the bipolar transport. Our temperature-dependent measurements confirmed the trap activation energy and provided the approximate functional form of electron and hole lifetimes as τe = 340 × (T/300 K)3/2 ns and τh = 100 × (T/300 K)–1/2 ns, for the temperature T range 80–800 K. It was found to hold for 65 and 120 μm sample thicknesses, while the lifetimes were found to be twice shorter for the sample 35 μm thick.



2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
E. Gaubas ◽  
T. Ceponis ◽  
V. Kalendra ◽  
J. Kusakovskij ◽  
A. Uleckas

Technique for barrier evaluation by measurements of current transients induced by linearly increasing voltage pulse based on analysis of barrier and diffusion capacitance changes is presented. The components of the barrier capacitance charging and generation/recombination currents are discussed. Different situations of the impact of deep center defects on barrier and diffusion capacitance changes are analyzed. Basics of the profiling of layered junction structures using the presented technique are discussed. Instrumentation for implementation of this technique and for investigations of the steady-state bias infra-red illumination and temperature dependent variations of the barrier capacitance charging and generation/recombination currents are described. Applications of this technique for the analysis of barrier quality in solar cells and particle detectors fabricated on silicon material are demonstrated.





2016 ◽  
Vol 952 ◽  
pp. 28-40 ◽  
Author(s):  
R. Gharaei ◽  
V. Zanganeh


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