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Browsing by Author "Mullen, K."

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  • Electrical characterization of organic based transistors: stability issues
    Publication . Gomes, Henrique L.; Stallinga, Peter; Dinelli, F.; Murgia, M.; Biscarini, F.; De Leeuw, D. M.; Muccini, M.; Mullen, K.
    An investigation into the stability of metal insulator semiconductor (MIS) transistors based on alpha-sexithiophene is reported. In particular the kinetics of the threshold voltage shift upon application of a gate bias has been determined. The kinetics follow a stretched-hyperbola type behavior, in agreement with the formalism developed to explain metastability in amorphous-silicon thin film transistors. Using this model, quantification of device stability is possible. Temperature-dependent measurements show that there are two processes involved in the threshold voltage shift, one occurring at T approximate to 220 K and the other at T approximate to 300 K. The latter process is found to be sample dependent. This suggests a relation between device stability and alpha-sexithiophene deposition parameters. Copyright (c) 2005 John Wiley A Sons, Ltd.
    2005Journal article Restricted access Show more
  • Interface state mapping in a Schottky barrier of the organic semiconductor terrylene
    Publication . Stallinga, Peter; Gomes, Henrique L.; Murgia, M.; Mullen, K.
    In this work we quantitatively map interface states in energy in a Schottky barrier between aluminum and the vacuum sublimed organic semiconductor terrylene. The density map of these interface states was extracted from the, admittance spectroscopy data. They revealed an interface state density of 2 x 10(12). cm(-2)eV(-1) close to the valence band which decreases slightly towards midgap. Additional do measurements show that the semiconductor bulk activation energy is 0.33 eV which may correspond to an acceptor level. (C) 2002 Elsevier Science B.V. All rights reserved.
    2002Journal article Restricted access Show more