Single-nanowire solar cells beyond the Shockley-Queisser limit
Abstract
Light management is of great importance in photovoltaic cells, as it determines the fraction of incident light entering the device. An optimal p-n junction combined with optimal light absorption can lead to a solar cell efficiency above the Shockley-Queisser limit. Here, we show how this is possible by studying photocurrent generation for a single core-shell p-i-n junction GaAs nanowire solar cell grown on a silicon substrate. At 1 sun illumination, a short-circuit current of 180 mA cm-2 is obtained, which is more than one order of magnitude higher than that predicted from the Lambert-Beer law. The enhanced light absorption is shown to be due to a light-concentrating property of the standing nanowire, as shown by photocurrent maps of the device. The results imply new limits for the maximum efficiency obtainable with III-V based nanowire solar cells under 1 sun illumination.
- Publication:
-
Nature Photonics
- Pub Date:
- April 2013
- DOI:
- 10.1038/nphoton.2013.32
- arXiv:
- arXiv:1301.1068
- Bibcode:
- 2013NaPho...7..306K
- Keywords:
-
- Condensed Matter - Mesoscale and Nanoscale Physics;
- Physics - Optics
- E-Print:
- 19 pages, 3 figures