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Silicon Heterojunction Microcells

Potter, Maggie M. and Phelan, Megan E. and Balaji, Pradeep and Jahelka, Phillip and Bauser, Haley C. and Glaudell, Rebecca D. and Went, Cora M. and Enright, Michael J. and Needell, David R. and Augusto, André and Atwater, Harry A. and Nuzzo, Ralph G. (2021) Silicon Heterojunction Microcells. ACS Applied Materials & Interfaces, 13 (38). pp. 45600-45608. ISSN 1944-8244. doi:10.1021/acsami.1c11122.

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We report the design, fabrication, and characterization of silicon heterojunction microcells, a new type of photovoltaic cell that leverages high-efficiency bulk wafers in a microscale form factor, while also addressing the challenge of passivating microcell sidewalls to mitigate carrier recombination. We present synthesis methods exploiting either dry etching or laser cutting to realize microcells with native oxide-based edge passivation. Measured microcell performance for both fabrication processes is compared to that in simulations. We characterize the dependence of microcell open-circuit voltage (V_(oc)) on the cell area–perimeter ratio and examine synthesis processes that affect edge passivation quality, such as sidewall damage removal, the passivation material, and the deposition technique. We report the highest Si microcell V_(oc) to date (588 mV, for a 400 μm × 400 μm × 80 μm device), demonstrate V_(oc) improvements with deposited edge passivation of up to 55 mV, and outline a pathway to achieve microcell efficiencies surpassing 15% for such device sizes.

Item Type:Article
Related URLs:
URLURL TypeDescription
Potter, Maggie M.0000-0002-6262-1078
Phelan, Megan E.0000-0002-4968-7128
Jahelka, Phillip0000-0002-1460-7933
Went, Cora M.0000-0001-7737-3348
Needell, David R.0000-0001-8343-5883
Atwater, Harry A.0000-0001-9435-0201
Nuzzo, Ralph G.0000-0003-2310-2045
Additional Information:© 2021 American Chemical Society. Received: July 20, 2021; Published: September 14, 2021. This work (design and fabrication of microcell materials, microcell modeling, and microcell characterization) has been primarily supported by the Photonics at Thermodynamic Limits Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under award number DE-SC0019140. A.A. acknowledges support from NSF and the Department of Energy (DOE) under NSF CA no. EEC-1041895 and DE-EE0008975. We acknowledge the Kavli Nanoscience Institute at Caltech for providing the infrastructure for part of this EFRC-funded work and helpful conversations with staff members Bert Mendoza, Nathan Lee, and Alex Wertheim. We would also like to thank the PPG-MRL Graduate Research Assistantship Award for supporting this project. Author Contributions: M.M.P. and M.E.P. contributed equally to the work. Conceptualization: M.M.P., M.E.P., H.A.A., and R.G.N. Methodology: M.M.P. and M.E.P. Investigation: M.M.P., M.E.P., R.D.G., P.B., and H.C.B. Resources: P.B. and A.A. Writing: M.M.P. and M.E.P. Review and editing: P.B., P.J., H.C.B., R.D.G., C.M.W., M.J.E., D.R.N., A.A., R.G.N., and H.A.A. Supervision: R.G.N. and H.A.A. Funding acquisition: R.G.N., H.A.A., and A.A. The authors declare no competing financial interest.
Group:Kavli Nanoscience Institute
Funding AgencyGrant Number
Department of Energy (DOE)DE-SC0019140
Department of Energy (DOE)DE-EE0008975
Subject Keywords:silicon heterojunction; microcell; photovoltaic; microfabrication; edge passivation
Issue or Number:38
Record Number:CaltechAUTHORS:20210917-215613739
Persistent URL:
Official Citation:Silicon Heterojunction Microcells. Maggie M. Potter, Megan E. Phelan, Pradeep Balaji, Phillip Jahelka, Haley C. Bauser, Rebecca D. Glaudell, Cora M. Went, Michael J. Enright, David R. Needell, André Augusto, Harry A. Atwater, and Ralph G. Nuzzo. ACS Applied Materials & Interfaces 2021 13 (38), 45600-45608; DOI: 10.1021/acsami.1c11122
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:110950
Deposited By: George Porter
Deposited On:20 Sep 2021 14:36
Last Modified:07 Oct 2021 21:44

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