NRL Achieves Highest Open-Circuit Voltage for Quantum Dot Solar Cells

WASHINGTON — (BUSINESS WIRE) — September 13, 2013 — U.S. Naval Research Laboratory (NRL) research scientists and engineers in the Electronics Science and Technology Division have demonstrated the highest recorded open-circuit voltages for quantum dot solar cells to date. Using colloidal lead sulfide (PbS) nanocrystal quantum dot (QD) substances, researchers achieved an open-circuit voltage (VOC) of 692 millivolts (mV) using the QD bandgap of a 1.4 electron volt (eV) in QD solar cell under one-sun illumination.

“These results clearly demonstrate that there is a tremendous opportunity for improvement of open-circuit voltages greater than one volt by using smaller QDs in QD solar cells,” said Woojun Yoon, Ph.D., NRC postdoctoral researcher, NRL Solid State Devices Branch. “Solution processability coupled with the potential for multiple exciton generation processes make nanocrystal quantum dots promising candidates for third generation low-cost and high-efficiency photovoltaics.”

Despite this remarkable potential for high photocurrent generation, the achievable open-circuit voltage is fundamentally limited due to non-radiative recombination processes in QD solar cells. To overcome this boundary, NRL researchers have reengineered molecular passivation in metal-QD Schottky junction (unidirectional metal to semiconductor junction) solar cells capable of achieving the highest open-circuit voltages ever reported for colloidal QD based solar cells.

Experimental results demonstrate that by improving the passivation of the PbS QD surface through tailored annealing of QD and metal-QD interface using lithium fluoride (LiF) passivation with an optimized LiF thickness. This proves critical for reducing dark current densities by passivating localized traps in the PbS QD surface and metal-QD interface close to the junction, therefore minimizing non-radiative recombination processes in the cells.

Over the last decade, Department of Defense (DoD) analyses and the department’s recent FY12 Strategic Sustainability Performance Plan, has cited the military’s fossil fuel dependence as a strategic risk and identified renewable energy and energy efficiency investments as key mitigation measures. Research at NRL is committed to supporting the goals and mission of the DoD by providing basic and applied research toward mission-ready renewable and sustainable energy technologies that include hybrid fuels and fuel cells, photovoltaics, and carbon-neutral biological microorganisms.

The Naval Research Laboratory is the Navy's full-spectrum corporate laboratory, conducting a broadly based multidisciplinary program of scientific research and advanced technological development. The Laboratory, with a total complement of nearly 2,500 personnel, is located in southwest Washington, D.C., with other major sites at the Stennis Space Center, Miss., and Monterey, Calif. NRL has served the Navy and the nation for over 85 years and continues to meet the complex technological challenges of today's world. For more information, visit the NRL homepage or join the conversation on Twitter, Facebook, and YouTube.



Contact:

U.S. Naval Research Laboratory
Daniel Parry, 202-767-2326
Email Contact




Review Article Be the first to review this article

Featured Video
Editorial
Jeff RoweJeff's MCAD Blogging
by Jeff Rowe
Siemens Goes ECAD With Mentor Graphics Acquisition
Jobs
Mechanical Engineer for IDEX Corporation at West Jordan,, UT
Senior Structural Engineer for Design Everest at San Francisco, CA
GIS Analyst II for Air Worldwide at Boston, MA
Business Partner Manager for Cityworks - Azteca Systems, LLC at Sandy, UT
Upcoming Events
Design & Manufacturing, Feb 7 - 9, 2017 Anaheim Convention Center, Anaheim, CA at Anaheim Convention Center Anaheim CA - Feb 7 - 9, 2017
Innorobo 2017 at Docks de Paris Paris France - May 16 - 18, 2017
Display Week 2017 at Los Angeles Convention Center 1201 S Figueroa St Los Angeles CA - May 21 - 26, 2017



Internet Business Systems © 2016 Internet Business Systems, Inc.
595 Millich Dr., Suite 216, Campbell, CA 95008
+1 (408)-337-6870 — Contact Us, or visit our other sites:
AECCafe - Architectural Design and Engineering EDACafe - Electronic Design Automation GISCafe - Geographical Information Services TechJobsCafe - Technical Jobs and Resumes ShareCG - Share Computer Graphic (CG) Animation, 3D Art and 3D Models
  Privacy Policy Advertise