Investigation of series resistance losses by illuminated lock‐in thermography

A measurement mode (JSC-ILIT) for the recently introduced Illuminated Lock-In Thermography (ILIT) method and a new interpretation of the images obtained is proposed. This mode is especially adapted for the investigation of series resistance, in particular contact resistance, in solar cells. Comparison of JSC-ILIT results to emitter potential maps obtained by Corescan demonstrate good agreement between the poorly contacted areas, proving the practical applicability of the technique. JSC-ILIT provides a quasi-contactless and fast measurement. Comparison is made with the recently introduced method of RS-ILIT. The capability of both methods to detect series resistance problems is demonstrated. Possible distortions due to inhomogeneities of bulk material quality are discussed. Copyright © 2005 John Wiley & Sons, Ltd.