Semiconducting temperature dependence

The thermistor pressure gauge (range 10 mbar to 10 3mbar) measures the temperature of a semiconducting temperature-dependent resistor wire. 

Better conductivity was obtained using the shorter-chain derivative C TCNQ. The composition of the complex was (TMTTF)3(Ci4TCNQ)2. The conductivity at room temperature reached 1 S/cm [156,157], which showed semiconducting temperature dependence with an activation energy AE = 0.06 eV. 

Temperature-dependent resistivity data (In p vs 1/T) for both Eu3lnP3 and Eu3ln2P4 are shown in Pig. 11.3 and indicate that they are semiconductors. The room-temperature resistivities are on the order of 1-100 cm. Band gaps were determined by fitting the data from about 130-300 K to the relationship. In p= Eg/ Ik T + f, providing a band gap. Eg, of approximately 0.5 eV for both samples. Since these two compounds can be rationalized as electron-precise Zintl phases, semiconducting behavior is expected. 

Measurements of the optical properties in this range of wavelengths can probe the fundamental electronic transitions in these nanostructures. Some of the aforementioned effects have in fact been experimentally revealed in this series of experiments (90). As mentioned above, the IF nanoparticles in this study were prepared by a careful sulfidization of oxide nanoparticles. Briefly, the reaction starts on the surface of the oxide nanoparticle and proceeds inward, and hence the number of closed (fullerene-like) sulfide layers can be controlled quite accurately during the reaction. Also, the deeper the sulfide layer in the nanoparticle, the smaller is its radius and the larger is the strain in the nanostructure. Once available in sufficient quantities, the absorption spectra of thin films of the fullerene-like particles and nanotubes were measured at various temperatures (4-300 K). The excitonic nature of the absorption of the nanoparticles was established, which is a manifestation of the semiconducting nature of the material. Furthermore, a clear red shift in the ex-citon energy, which increased with the number of sulfide layers of the nanoparticles, was also observed (see Fig. 21). The temperature dependence of the exciton... 

Another semiconducting fulleride salt, [Ru(bpy)3](C5o)2 with bpy = 2,2 -bipyridine, crystallizes on the Pt electrode surface out of dichloromethane solutions saturated with [Ru(bpy)3]PF5 within a few minutes [79]. The NIR spectra of benzonitrile solutions of this salt demonstrate that the only fulleride anion present is 55 . The temperature dependence of the conductivity is typical for a semiconductor, with the room temperature conductivity being 0.01 S cm and the activation energy 0.1 kj mol (0.15 eV). It was postulated that there is an electronic overlap between the two ions of this salt leading to a donation of electron density from the 55 to the ligand orbitals in the [Ru(bpy)3] " AI 0.7) [79]. 

Blakesley JC, Clubb HS, Greenham NC (2010) Temperature-dependent electron and hole transport in disordered semiconducting polymers analysis of energetic disorder. Phys Rev B 81 045210... 

As the first insulating/semiconducting higher boride series, the electrical transport of these compounds has been carefully investigated (e.g. Slack et al., 1977 Golikova, 1987 Werheit et al., 1991). The temperature dependence of the resistivity p follows the dependency of Mott s variable range hopping (VRH) model for 3 dimensional systems (Mott, 1968 Efros and Shklovskii, 1985), where... 

In the case of intrinsic band conduction the experimental activation energy SA is identified with half the band gap (Eq. (2.37)) in the case of extrinsic or impurity semiconductivity, SA is either half the gap between the donor level and the bottom of the conduction band or half the gap between the acceptor level and the top of the valence band, depending upon whether the material is n or p type. In such cases the temperature dependence is determined by the concentration of electronic carriers in the appropriate band, and not by electron or hole mobility. 

The temperature dependence of reflectance and conductivity spectra of P(ET)2 i3 are very illuminating indeed (Fig. 27). At room temperature o-(ot)) reveals a semiconducting behavior with a peak of conductivity at 2000 cm-1 while an approximate metallic behavior is obtained at low temperature the plasma frequency remains almost temperature independent. 

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