Application of lateral photovoltage towards contactless light beam induced current measurements and its dependence on the finite beam size

Abhale, Atul Prakash and Rao, Koteswara KSR (2014) Application of lateral photovoltage towards contactless light beam induced current measurements and its dependence on the finite beam size. In: REVIEW OF SCIENTIFIC INSTRUMENTS, 85 (7).

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Abstract

The nature of the signal due to light beam induced current (LBIC) at the remote contacts is verified as a lateral photovoltage for non-uniformly illuminated planar p-n junction devices; simulation and experimental results are presented. The limitations imposed by the ohmic contacts are successfully overcome by the introduction of capacitively coupled remote contacts, which yield similar results without any significant loss in the estimated material and device parameters. It is observed that the LBIC measurements introduce artefacts such as shift in peak position with increasing laser power. Simulation of LBIC signal as a function of characteristic length L-c of photo-generated carriers and for different beam diameters has resulted in the observed peak shifts, thus attributed to the finite size of the beam. Further, the idea of capacitively coupled contacts has been extended to contactless measurements using pressure contacts with an oxidized aluminium electrodes. This technique avoids the contagious sample processing steps, which may introduce unintentional defects and contaminants into the material and devices under observation. Thus, we present here, the remote contact LBIC as a practically non-destructive tool in the evaluation of device parameters and welcome its use during fabrication steps. (C) 2014 AIP Publishing LLC.

Item Type:	Journal Article
Publication:	REVIEW OF SCIENTIFIC INSTRUMENTS
Additional Information:	Copy right for this article belongs to the AMER INST PHYSICS, CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	10 Oct 2014 09:13
Last Modified:	10 Oct 2014 09:13
URI:	http://eprints.iisc.ac.in/id/eprint/49987

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