Author
R C Goodfellow
Bio: R C Goodfellow is an academic researcher. The author has co-authored 1 publications.
Papers
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TL;DR: In this article, the authors demonstrate the sensitive dependence of the onset time for deviations from ohmic current values in thin acoustoelectrically active photoconducting CdS platelets, on the optical absorption of the photoexciting illumination used.
Abstract: Results are presented which demonstrate the sensitive dependence of the onset time td for deviations from ohmic current values in thin acoustoelectrically active photoconducting CdS platelets, on the optical absorption of the photoexciting illumination used. Computations, based on a theoretical model of linear round-trip acoustoelectric gain in thin platelets having exponential conductivity profiles parallel to the current flow, give semiquantitive agreement with experimental curves obtained using narrow-band illumination with measured optical absorbance values. A number of experimental and theoretical reasons are provided in explanation for the lack of precise agreement. By the use of very weakly absorbed illumination and carefully prepared specimen contacts, excellent agreement is obtained between the experimental dependence on conductivity of threshold and cut-off voltages for acoustoelectric activity, and the predictions of the linear gain model with drift mobility as a `fitting' parameter. By the assumption of a reasonable value for the non-electronic acoustic loss, a reasonable fit is also obtained between experimental and theoretically predicted values of the voltage for minimum onset time.