Berlin 2008 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 12: Photovoltaic

HL 12.7: Vortrag

Montag, 25. Februar 2008, 15:30–15:45, EW 202

Locally resolved characterization of CuInS2 thin film solar cells — •Markus Wendt, Jo Klaer, Thomas Unold, and Hans Werner Schock — Hahn-Meitner-Institut Berlin Glienicker Str. 100 14109 Berlin

CuInS2 thin film solar cells were produced by sulfurization of metallic precursor layers using a rapid thermal anneal process. Depending on the processing conditions variations of the total photocurrent were found. At the same time, scanning electron microscopy revealed an inhomogeneous morphology for many of the solar cells processed. To investigate the influence of processing conditions on the photocurrent collection in more detail, laser beam induced current (LBIC) measurements were applied to selected solar cells. The excitation wavelength was 525nm and the local resolution was 1-3 um. The typical scanning range of the experiments was 1sq.mm. LBIC-maps collected at low light-intensities of approximately 1 sun showed variations of 5% in the local photocurrent collection. However, LBIC maps at high intensities of approximately 1000 suns showed very large variations in the local photocurrent collection of nearly a factor of 2-3. We conclude that the local variation of current collection under high illumination is due to current crowding effects caused by inhomogeneities in the morphology of the solar cells.