Presentation Details
| New Methods for Interpreting Surface Photovoltage Spectra for Contactless Device Characterization Nathan Rock1, Michael Scarpulla1, 2. 1University of Utah Dept.of Materials Science and Engineering, Salt Lake City, UT, USA.2University of Utah Dept.of Electrical and Computing Engineering, Salt Lake City, UT, USA |
Abstract
We summarize the development of new methods of analyzing surface photovoltage spectroscopic signals, as part of our grant under the Department of Energy’s Cadmium Telluride Accelerator Consortium. We derive a simple approximation relating surface photovoltage to the logarithm of IQE. This model is validated and it’s limitations explored through rigorous numerical modeling in SCAPS-1D Poisson Drift Diffusion solver as well as through direct experimental comparison of surface photovoltage and IQE measurements. In a separate project, surface photovoltage spectra are modeled in SCAPS-1D, exploring a wide range of values for critical parameters. These modeled spectra are tested against real world experiment employing Bayesian Parameter Inference to not only arrive at a global best fit for all parameter combination, but also to define confidence intervals for each parameter explored. These results provide a degree of statistical rigor to the measurement of critical device parameters such as minority carrier mobility which has thus far been lacking in SPV analysis.
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No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author.