Temperature dependence of carrier

A.K. Kapoor, S.C. Jain, J. Poortmans, V. Kumar, R. Mertens, Temperature dependence of carrier transport in conducting polymers Similarity to amorphous inorganic semiconductors, J. Appl. Phys. 92 (2002) 3835. 

The gap Eq is not the minimum gap Eg which determines the absorption edge and temperature dependence of carrier concentration, but the average gap corresponding to the separation of the bonding and antibonding states in the covalent bond picture. It has fundamental importance for many basic properties of the solid and appears in the theories of the relation between the chemical and optical properties of crystals (Phillips (1970)). 

Fig.tr.1-3tr 3C-S1C. Temperature dependence of carrier concentration for n-type films grown by CVD on Si(lOO) substrates [1.25]. Solid lines, calculated values. Si/C = ratio of source gases... 

Figure 13 Electrical properties of n- and p- BP (111) wafers before and after irradiation by thermal neutrons. The temperature dependence of carrier densities with calculated values is denoted by dashed curves. (From Ref. 61.)...

With the Monte Carlo method, the sample is taken to be a cubic lattice consisting of 70 x 70 x 70 sites with intersite distance of 0.6 nm. By applying a periodic boundary condition, an effective sample size up to 8000 sites (equivalent to 4.8-p.m long) can be generated in the field direction (37,39). Carrier transport is simulated by a random walk in the test system under the action of a bias field. The simulation results successfully explain many of the experimental findings, notably the field and temperature dependence of hole mobilities (37,39). 

The responsivity and g-r noise may be analyzed to obtain background photon flux and temperature dependence of responsivity, noise, and detectivity. Typically, n > p, and both ate determined by shallow impurity levels. The minority carrier density is the sum of thermal and optical contributions. 

Above 2 K, the temperature dependence of the zero-field resistivity of the microbundle measured by Langer et al. [9] was found to be governed by the temperature dependence of the carrier densities and well described by the simple two-band (STB) model derived by Klein [23] for electrons, , and hole, p, densities in semimetallic graphite ... 

So, despite the very small diameter of the MWCNT with respeet to the de Broglie wavelengths of the charge carriers, the cylindrical structure of the honeycomb lattice gives rise to a 2D electron gas for both weak localisation and UCF effects. Indeed, both the amplitude and the temperature dependence of the conductance fluctuations were found to be consistent with the universal conductance fluctuations models for mesoscopic 2D systems applied to the particular cylindrical structure of MWCNTs [10]. 

In the following, we shall describe separately the temperature dependence of the contributions to the thermal conductivity for the two heat carriers . In the case of phonons, the Debye temperature 0D will be taken as a reference in analysing the temperature dependence of the thermal conductivity. 

Figure 3. (a) Representation of the hexagonal discotic mesophase formed by hexadodecyl substituted HBC 33. (b) The temperature dependence of the intracolumnar charge carrier mobilities for 33 and 34. Phase transition tempera-... 

Detailed study [18] of the system isobutene-titanium tetrachloride-water-methylene dichloride showed it to be highly complex, but the kinetics and the temperature-dependence of rate and DP could be explained, at least qualitatively, on the hypotheses that the chain-carriers are ions, that paired and free cations have appreciably different reactivities, and that the degree of dissociation of the ion-pairs increases with decreasing temperature. 

---