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Journal of Photonics for Energy • Open Access

Optical technique for photovoltaic spatial current response measurements using compressive sensing and random binary projections
Author(s): Matt T. Cashmore; George Koutsourakis; Ralph Gottschalg; Simon R. G. Hall

Paper Abstract

Compressive sensing has been widely used in image compression and signal recovery techniques in recent years; however, it has received limited attention in the field of optical measurement. This paper describes the use of compressive sensing for measurements of photovoltaic (PV) solar cells, using fully random sensing matrices, rather than mapping an orthogonal basis set directly. Existing compressive sensing systems optically image the surface of the object under test, this contrasts with the method described, where illumination patterns defined by precalculated sensing matrices, probe PV devices. We discuss the use of spatially modulated light fields to probe a PV sample to produce a photocurrent map of the optical response. This allows for faster measurements than would be possible using traditional translational laser beam induced current techniques. Results produced to a 90% correlation to raster scanned measurements, which can be achieved with under 25% of the conventionally required number of data points. In addition, both crack and spot type defects are detected at resolutions comparable to electroluminescence techniques, with 50% of the number of measurements required for a conventional scan.

Paper Details

Date Published: 29 June 2016
PDF: 8 pages
J. Photon. Energy 6(2) 025508 doi: 10.1117/1.JPE.6.025508
Published in: Journal of Photonics for Energy Volume 6, Issue 2
Show Author Affiliations
Matt T. Cashmore, National Physical Lab. (United Kingdom)
George Koutsourakis, Loughborough Univ. (United Kingdom)
Ralph Gottschalg, Loughborough Univ. (United Kingdom)
Simon R. G. Hall, National Physical Lab. (United Kingdom)

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