Engineering

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  • Quantitative analysis of electron-beam-induced-current profiles of grain boundariesin multicrystalline solar cells
    (1998) Corkish, Richard; Sproul, Alistair; Puzzer, Tom; Altermatt, Peter; Heiser, Gernot; Luke, Keung
    Conference Paper
  • Electron-Beam-Induced Current Studies of Grain Boundaries in Solar Cells
    (1997) Corkish, Richard; Puzzer, Tom; Sproul, Alistair; Luke, Keung; Heiser, Gernot
    Conference Paper
  • Grain boundary modelling and characterization of thin-film silicon solar cell
    (1996) Sproul, Alistair; Edminston, Sean; Puzzer, Tom; Heiser, Gernot; Wenham, Stuart; Green, Martin; Young, Timothy
    Conference Paper
    An analytical model is developed to decribe recombination currents arising from recombination at grain boundaries (GBs) in the depletion region of a p-n junction solar cell. Grain boundaries are modelled as having a single energy evel in the energy gap, and partial occupancy of these stats gives raise to a chage on the GB. The analytical model is compared to a complete numerical simulation package (DESSIS) and found to be in excellent agreement. Additionally,. cross sectional EBIC images of a multilayer device containing vertical GBs are presented. The experimental data is comared qualitatively with results derived from numerical modelling.
  • Vortex-glass state in BSCCO single crystals with CuO trilayers
    (1995) Han, Shaowei; Zhao, Yong; Gu, Genda; Russell, Graeme; Koshizuka, N
    Conference Paper
  • Asymptotic power spectrum analysis of electrical noise in vortex state of Bi2Sr2CaCuO single crystals
    (1995) Zhao, Yong; Gu, Genda; Han, Shaowei; Russell, Graeme; Koshizuka, N
    Conference Paper
    The voltage noise of a Bi2Sr2CaCu2O8+x single crystal below Tcis analyzed with an asymptotic power spectrum method. Low-frequency noise power Sv(T) shows a peak at T = Tp. Above Tp, the power spectrum, Sv(f), exhibits a power-law fall-off. Below Tp, Sv() dramatically deviates from the power-law behaviour, showing some wide peaks which are proposed upon a background of an exponential-law characteristic. This is qualitatively consistent with numerical simulation. It is suggested that the pinned vortex state is a deterministic motion with low-dimensional chaotic attractors while the unpinned state is an extended dissipative dynamic system with self-organized criticality.
  • Giant resistive Peak close to the superconducting transition in Bi2Sr2CaCo2O single crystal
    (1995) Han, Shaowei; Zhao, Yong; Gu, Genda; Russell, Graeme; Koshizuka, N
    Conference Paper
  • Superconducting fluctuations in Bi2Sr2CaCu2o single crystals with different anisotropy
    (1995) Han, Shaowei; Zhao, Yong; Gu, Genda; Russell, Graeme; Koshizuka, N
    Conference Paper
  • Vortex-glass state in BSCCO single crystals with CuO2 trilayers
    (1995) Han, Shaowei; Zhao, Yong; Gu, Genda; Russell, Graeme; Koshizuka, N
    Conference Paper
  • Power spectrum of voltage noise and vortex state of BixSr2CaCu2O8+x single crystals
    (1995) Zhao, Yong; Gu, Genda; Han, Shaowei; Russell, Graeme; Koshizuka, N
    Conference Paper
  • Real time measurements of vocal tract resonances during speech
    (1997) Epps, Julien; Dowd, Annette; Smith, John; Wolfe, Joseph
    Conference Paper
    The formants of speech sounds are usually attributed to resonances of the vocal tract. Formant frequencies are usually estimated by inspection of spectrograms or by automated techniques such as linear prediction. In this paper we measure the frequencies of the first two resonances of the vocal tract directly, in real time, using acoustic impedance spectrometry. The vocal tract is excited by a carefully calibrated, broad band, acoustic current signal applied outside the lips while the subject is speaking. The sound pressure response is analysed to give the resonant frequencies. We compare this new method (Real-time Acoustic Vocal tract Excitation or RAVE) with linear prediction and we report the vocal tract resonances for eleven vowels of Australian English. We also report preliminary results of using feedback from vocal tract excitation as a speech trainer, and its effect on improving the pronunciation of foreign vowel sounds by monolingual anglophones.