Application of a dual-spectral-range, divergent-beam spectroscopic ellipsometer for high-speed mapping of large-area, laterally-inhomogeneous, photovoltaic multilayers

M. Fried, G. Juhasz, C. Major, A. Nemeth, P. Petrik, O. Polgar, C. Salupo, Lila R. Dahal, R. W. Collins

Research output: Chapter in Book/Report/Conference proceedingConference contribution

7 Citations (Scopus)

Abstract

We have developed a prototype spectroscopic ellipsometer for imaging/mapping purposes requiring only one measurement cycle (one rotation period of a polarizer or analyzer) for the acquisition of a two-dimensional array of data points. Our new measurement technique serves as a novel form of imaging ellipsometry, using a divergent (uncollimated, diffuse) source system and a detection system consisting of an angle-of-incidence-sensitive pinhole camera. By incorporating broad-band sources and wavelength dispersion optics, the instrument provides continuous high-resolution spectra along a line image of the sample surface. As a result, information on multilayer photovoltaics stacks can be obtained over large areas (several dm 2) at high speed. The technique can be expanded to even larger areas by scaling-up the optical geometry. The spatial resolution of the line image is limited by the minimum resolved-angle as determined by the detection system. Small-aperture polarizers (25 mm diameter) are incorporated into the instrument, which reduces its cost. Demonstration mapping measurements have been performed ex situ on a multilayer sample deposited on a polymer substrate, including an intentionally graded 80-350 nm thick hydrogenated amorphous silicon (a-Si:H) layer and an intended uniform 400-500 nm thick transparent conducting ZnO:Al layer, both on opaque silver. Alternative commercial instruments for ex situ SE mapping must translate the sample in two dimensions. Even a 15 x 15 cm 2 sample requires > 200 measurements with cm-resolution and at least 15 min. By collecting ex situ data in parallel along one dimension through imaging, the divergent-beam system can measure with similar spatial resolution in < 2 min. In situ measurements on both roll-to-roll polymer and rigid glass will be possible in the future.

Original languageEnglish
Title of host publicationAdvanced Materials Processing for Scalable Solar-Cell Manufacturing
Pages157-162
Number of pages6
DOIs
Publication statusPublished - Jan 1 2012
Event2011 MRS Spring Meeting - San Francisco, CA, United States
Duration: Apr 25 2011Apr 29 2011

Publication series

NameMaterials Research Society Symposium Proceedings
Volume1323
ISSN (Print)0272-9172

Other

Other2011 MRS Spring Meeting
CountryUnited States
CitySan Francisco, CA
Period4/25/114/29/11

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ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

Fried, M., Juhasz, G., Major, C., Nemeth, A., Petrik, P., Polgar, O., Salupo, C., Dahal, L. R., & Collins, R. W. (2012). Application of a dual-spectral-range, divergent-beam spectroscopic ellipsometer for high-speed mapping of large-area, laterally-inhomogeneous, photovoltaic multilayers. In Advanced Materials Processing for Scalable Solar-Cell Manufacturing (pp. 157-162). (Materials Research Society Symposium Proceedings; Vol. 1323). https://doi.org/10.1557/opl.2011.820