Impact of laterally non-uniform carrier lifetime on photoconductance-based lifetime measurements with self-consistent calibration

Authors

  • W. S. Liang,

    Corresponding author
    1. Centre for Sustainable Energy Systems, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory, Australia
    • Correspondence: Wensheng Liang, Centre for Sustainable Energy Systems, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory 0200, Australia.

      E-mail: wensheng.liang@anu.edu.au

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  • Klaus J. Weber,

    1. Centre for Sustainable Energy Systems, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory, Australia
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  • Y. L. Ren

    1. Centre for Sustainable Energy Systems, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory, Australia
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ABSTRACT

The impact of laterally non-uniform carrier lifetime on the determination of the lifetime from photoconductance-based measurements, based on the self-consistent method proposed by Trupke and Bardos, is investigated using a simple model. It is shown that the method can result in an overestimation of the mean lifetime, with the magnitude of the error mainly dependent on the distribution of the effective lifetime across the area sensed by the photoconductance coil. Although in many cases the error introduced will be relatively small (in the order of 5% or less), much larger errors can result in some cases, such as for samples that feature small areas with a significantly higher than average lifetime. The error can be eliminated through independent measurement of the sample optical properties. Experimental measurements confirm the model predictions. Copyright © 2012 John Wiley & Sons, Ltd.

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