A new metal transfer process for van der Waals contacts to vertical Schottky-junction transition metal dichalcogenide photovoltaics
Abstract
Two-dimensional transition metal dichalcogenides are promising candidates for ultrathin optoelectronic devices due to their high absorption coefficients and intrinsically passivated surfaces. To maintain these near-perfect surfaces, recent research has focused on fabricating contacts that limit Fermi-level pinning at the metal-semiconductor interface. Here, we develop a new, simple procedure for transferring metal contacts that does not require aligned lithography. Using this technique, we fabricate vertical Schottky-junction WS₂ solar cells, with Ag and Au as asymmetric work function contacts. Under laser illumination, we observe rectifying behavior and open-circuit voltage above 500 mV in devices with transferred contacts, in contrast to resistive behavior and open-circuit voltage below 15 mV in devices with evaporated contacts. One-sun measurements and device simulation results indicate that this metal transfer process could enable high specific power vertical Schottky-junction transition metal dichalcogenide photovoltaics, and we anticipate that this technique will lead to advances for two-dimensional devices more broadly.
Additional Information
© 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited. Submitted 8 April 2019; Accepted 30 October 2019; Published 20 December 2019. We thank S. Nam for the useful discussions. This work was supported by the DOE "Photonics at Thermodynamic Limits" Energy Frontier Research Center under grant DE-SC0019140. C.M.W. and J.W. acknowledge support from the NSF Graduate Research Fellowship under grants 1745301 and 1144469. C.M.W. acknowledges fellowship support from the Resnick Sustainability Institute. Author contributions: C.M.W. fabricated the devices, performed the measurements, and performed the simulations. C.M.W., J.W., P.R.J., and S.B. developed the metal transfer technique. J.W. and P.R.J. assisted with the simulations. M.K. assisted with the solar simulator, absorption, and EQE measurements. M.S.H. and A.C. assisted with the TEM sample preparation and imaging. H.A.A. supervised all the experiments, calculations, and data collection. All authors contributed to the data interpretation, presentation, and writing of the manuscript. The authors declare that they have no competing interests. Data and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials. Additional data related to this paper may be requested from the authors.Attached Files
Published - aax6061.pdf
Submitted - 1903.08191.pdf
Supplemental Material - aax6061_SM.pdf
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Additional details
- Alternative title
- Transferred metal contacts for vertical Schottky-junction transition metal dichalcogenide photovoltaics
- PMCID
- PMC6924982
- Eprint ID
- 95420
- DOI
- 10.1126/sciadv.aax6061
- Resolver ID
- CaltechAUTHORS:20190513-082509112
- Department of Energy (DOE)
- DE-SC0019140
- NSF Graduate Research Fellowship
- DGE-1745301
- NSF Graduate Research Fellowship
- DGE-1144469
- Resnick Sustainability Institute
- Created
-
2019-05-13Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field
- Caltech groups
- JCAP, Resnick Sustainability Institute