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A physically based compact mobility model for organic thin-film transistors (OTFTs) with an analysis of bias-dependent Fermi-energy ( EF ) movement in the bandgap ( Eg ) is presented. Mobility in the localized and extended energy states predicts the drain-current behavior in the weak and strong accumulation operations of OTFTs, respectively. A hopping mobility model as a function of the surface potential is developed to describe the carrier transport through localized energy states located inside Eg . The Poole–Frenkel parallel-field-effect mobility and vertical-field-effect mobility are considered to interpret the bandlike carrier transport in the extended energy states. The parallel field effect on mobility is more pronounced for shorter channel length OTFTs and is considered by developing a channel-length-dependent mobility model. The vertical field effect on mobility is included to account for the effect of mobility on carrier transport at high gate-voltage-induced fields. We also compared the model results with 2-D device simulations and measurements to verify the developed mobility model. [ABSTRACT FROM AUTHOR]

A compact surface potential based model for organic thin-film transistors (OTFTs), including both tail and deep trap states across the band gap, is reported. The model has been developed on the basis of a complete surface potential approach for undoped-body OTFTs. Accurate surface potentials are calculated by explicitly including the floating backside potential that varies with applied biases. A pseudo-2D resistor model is developed to capture the structural features of the OTFT. The resistor model considers, in particular, the effects originating from a bias dependent 2D current flow in the channel region and results in accurate reproduction of the electrical characteristics. The fitting capability of the developed OTFT model is verified against measured high-performance dinaphtho thieno thiophene (DNTT) based field-effect transistor data. Accurate reproduction of the current characteristics of the OTFT test structures is verified from a week to a strong inversion regime. [ABSTRACT FROM PUBLISHER]

Based on ab initio formulation and using nonequilibrium Green's function (NEGF) formalism, electronic transport in the presence of electron-phonon interactions in strained-engineered nanoscale transistors is presented. Ab initio methods are applied to treat the metal/semiconductor interface properly. NEGF formalism is applied as quantum transport and phonon scattering are the dominant factors in devices under realistic operating voltages. Local self-energy functions for electron-phonon scattering have been obtained using deformation potential theory. This approach is applied to the study of electronic transport in strain-engineered nanowire transistors. Electron-phonon interactions on broadening of local density of states are also reported. [ABSTRACT FROM AUTHOR]

Mushroom glucan and bovine lactoferrin (Lf), known for their immunostimulatory potential, were used as adjuvant in conjunction with a formalin-killed Aeromonas hydrophila vaccine in catla, Catla catla. In vitro antigen-specific responsiveness of catla leucocytes and protective responses against experimental challenge with homologous antigen were monitored following immunization. Antigen-specific proliferation, ‘macrophage activating factor’ (MAF) production and antibody production were significantly higher in fish injected with glucan adjuvanted vaccine. Lf adjuvanted preparations showed a weak proliferative response and MAF production, although the antibody production was significantly higher than the controls. A good degree of protection was achieved with the glucan adjuvanted vaccine. However, in spite of producing significant anti- A. hydrophila antibody, Lf adjuvanted vaccine did not confer any protection following challenge with A. hydrophila. The potential of adjuvanticity of mushroom glucan and bovine Lf in intraperitoneal vaccination is discussed. [ABSTRACT FROM AUTHOR]

Agglutinin and toxin was isolated and purified from Abrus precatorius seeds using conventional biochemical techniques such as Sepharose 4B affinity chromatography, Sephadex G-100 gel filtration and analytical HPLC chromatography. The yield of purified agglutinin was 272 mg per 50 g of seeds which was composed of 8.0% agglutinin and 6.1% toxin. SDS gel electrophoresis of purified protein under reducing and non-reducing conditions of native and denatured protein revealed four bands with molecular weights ranging from 31 to 66 kDa by protein and glycoprotein staining procedures. The adjuvant property of abrus agglutinin was evaluated using rat as an animal model, in comparison with Freund's complete adjuvant. Ovalbumin was used as a test antigen and was injected along with Freund's complete adjuvant (Group I experimental animals) and along with denatured abrus protein (Group II experimental animals). The humoral response was compared between two groups of animals (Group I and II) for total (by sandwich ELISA) and specific response (by antibody capture assay). Group II animals which received denatured abrus protein along with test antigen showed a significantly higher IgG response of 23.0 +/- 2.37 mg ml[sup -1] (p < 0.001) when compared to Group I animals (14.0 +/- 2.50 mg ml[sup -1]). However, there was no statistically significant difference between Group I and Group II, with respect to specific IgG response to test antigen. Thus, the present investigation suggests that the denatured abrus agglutinin can be used as an effective alternative protein adjuvant. [ABSTRACT FROM AUTHOR]

Defects and traps in strained-Si n-type metal-oxide-semiconductor field effect transistors (MOSFETs) are studied in detail. The inelastic electron tunneling spectroscopy (IETS) technique is shown to be capable of probing traps in ultrathin gate dielectrics and obtain the energies and spatial locations of the traps. Detailed analyses of electrical stress-induced build-up of traps and electrically active bonding defects and identification of the trap-features including trap-assisted conduction and charge-trapping have been performed. The location and energies of the traps are estimated from the IETS spectra measured at both bias polarities. Identification of the acoustic and optical phonon modes (inelastic) as well as trap-features (elastic) helps in better understandings of the complex transport-mechanisms in gate dielectrics on strained layers. [ABSTRACT FROM AUTHOR]