Presentation Details
| Transition Metal Dichalcogenide Photovoltaics with Carrier-Selective Contacts and Indium Tin Oxide Superstrates (yes) Rachel W.Tham, Belle Chen, Michael K.Kelzenberg, Phillip R.Jahelka, Susana Torres-Londono, Cora M.Wyent, Harry A.Atwater. Caltech, Pasadena, CA, USA |
Abstract
Transition Metal Dichalcogenides (TMDs) are two-dimensional semiconducting materials that exhibit high absorption coefficients promising for ultrathin, high-specific-power photovoltaics. Many literature-reported TMD solar cells rely on Schottky and p-n junction configurations where the TMD-metal interface exhibit significant recombination losses that limit the solar cell performance. To overcome these losses, we recently demonstrated the first-to-date dual carrier-selective contact TMD vertical solar cell using a tungsten disulfide TMD absorber with PTAA and C60 transport layers. In this work, to improve the performance of the dual selective contact TMD solar cell, we focus on increasing the short-circuit current density (JSC) and fill factor. With Transfer Matrix Method calculations, we find that by changing the solar cell architecture to include a tungsten diselenide (WSe2) TMD absorber with an Indium Tin Oxide (ITO) superstrate and top silver mirror, we can increase the TMD absorption and achieve an AM1.5G Jsc of at least 23 mA/cm2. We start with experimentally fabricating and testing an ITO solar cell design with WSe2 and a PTAA selective contact. Under about a three-quarter-sun illumination intensity, this solar cell exhibits a Voc of about 420 mV, Jsc of about 24 mA/cm2, and fill factor of about 57%. To improve the fill factor, we explore using oxide-based selective contacts, such as titanium dioxide, in addition to annealing methods, to more controllably tune the selective contact conductance. Finally, we discuss how we can achieve both higher JSC and fill factors by implementing oxide-based selective contacts on ITO superstrates.
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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.