9 research outputs found
Combination of light-induced effect and gate bias stress in organic phototransistors
In this work, the photoresponse of pentacene-based thin film transistors fabricated with a photocurable polymer insulator was investigated under visible and ultraviolet illumination. A simple model was developed to distinguish a photoconductive and a photovoltaic effect, that is, a direct photocurrent and a current enhancement caused by a threshold voltage shift. The direction of the light-induced threshold translation is affected by measurement conditions (e.g. integration time and voltage range) and is related to the nature of the trap states, specifically those located in the pentacene film near the interface with the polymer. In particular, it was shown that, thanks to this phenomenon, the photosensitivity of the fabricated phototransistors could be modulated by the gate bias applied during illumination
Growth and production of the venerid bivalve Eurhomalea exalbida in the Beagle Channel, Tierra del Fuego
Growth, mortality and productivity of the hard clam E. exalbida from Ushuaia Bay, Beagle Channel were investigated. The parameters of the von Bertalanffy growth function were estimated to be H = 73.98 mm, K = 0.180 y 1, t0 = 0.147 y. Maximum individual production amounted to 2.742 g shell free wet mass (SFWM) at 49.5 mm shell height. Animals between 40 mm and 70 mm shell height contribute most to overall population somatic production P of 133.89 g SFWM m-2 y-1. Mean annual biomass B amounted to 1122.69 g SFWM m-2 y-1. Annual P/B ratio and mortality rate Z were estimated to 0.119 y-1 and 0.141 y-1, respectively. Slow growth and low turnover makes this population less suitable for sustainable commercial exploitation
Microstructure and interface studies of <tex>LaVO_{3}/SrVO_{3}$</tex> superlattices
International audienceThe structure and interface characteristics of (LaVO3)6m(SrVO3)m superlattices deposited on a (100)-SrTiO3 substrate were studied using transmission electron microscopy (TEM). Cross-section TEM studies revealed that both LaVO3 (LVO) and SrVO3 (SVO) layers are good single-crystal quality and epitaxially grown with respect to the substrate. It is evidenced that LVO layers are made of two orientational variants of a distorted perovskite compatible with bulk LaVO3, while SVO layers suffers from a tetragonal distortion due to the substrate-induced stain. Electron energy loss spectroscopy investigations indicate changes in the fine structure of the V L23 edge, related to a valence change between the LaVO3 and the SrVO3 layers