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Transferred Metal Contacts for Ultrathin Solar Cells

March 04, 2020

Research Overview

RSI Fellow Cora Went

Graduate student and Cross-Resnick Fellow, Cora Went, is a member of a research team that developed a simple method for transferring metal contacts onto 2D materials and applied the technique to make ultrathin solar cells. The results of this study have been summarized in the publication,"A New Metal Transfer Process for Van Der Waals Contacts to Vertical Schottky-Junction Transition Metal Dichalcogenide Photovoltaics." The team anticipates that the technique will broadly lead to advances for 2D devices.

Scientific Achievement

We developed a simple method for transferring metal contacts onto 2D materials and used this technique to make ultrathin solar cells.

Metal transfer process.
Metal transfer process. Credit: Reprinted with permission from Science Advances: https://advances.sciencemag.org/content/5/12/eaax6061

Significance and Impact

We performed one of the first characterizations of 2D solar cells under one-sun illumination and created a useful technique for 2D researchers.

Transferred-contact devices show diode-like IV curves and open-circuit voltage > 500 mV. Evaporated-contact devices show resistive IV curves and open-circuit voltage below 15 mV.
Transferred-contact devices show diode-like IV curves and open-circuit voltage > 500 mV. Evaporated-contact devices show resistive IV curves and open-circuit voltage below 15 mV. Credit: Reprinted with permission from Science Advances: https://advances.sciencemag.org/content/5/12/eaax6061

Ultrathin (<150 nm) solar cells made from 2D semiconductors with transferred contacts. Left, schematic. Right, photogenerated current mapping.
Ultrathin (<150 nm) solar cells made from 2D semiconductors with transferred contacts. Left, schematic. Right, photogenerated current mapping. Credit: Reprinted with permission from Science Advances: https://advances.sciencemag.org/content/5/12/eaax6061

Technical Details

  • Transferring metal contacts creates metal-2D semiconductor interfaces free of Fermi level pinning.
  • We measured active-layer internal quantum efficiency >90%, demonstrating efficient carrier collection.
  • We measured a power conversion efficiency of 0.5%, comparable to other ultrathin 2D photovoltaics.

C. M. Went, J. Wong, P. R. Jahelka, M. Kelzenberg, S. Biswas, M. S. Hunt, A. Carbone, H. A. Atwater, A new metal transfer process for van der Waals contacts to vertical Schottky-junction transition metal dichalcogenide photovoltaics. Sci. Adv. 5, eaax6061 (2019). https://doi.org/10.1126/sciadv.aax6061

Contact: Harry A. Atwater