Si microwire-array solar cells
Abstract
Si microwire-array solar cells with Air Mass 1.5 Global conversion efficiencies of up to 7.9% have been fabricated using an active volume of Si equivalent to a 4 μm thick Si wafer. These solar cells exhibited open-circuit voltages of 500 mV, short-circuit current densities (J_(sc)) of up to 24 mA cm^(-2), and fill factors >65% and employed Al_2O_3 dielectric particles that scattered light incident in the space between the wires, a Ag back reflector that prevented the escape of incident illumination from the back surface of the solar cell, and an a-SiN_x:H passivation/anti-reflection layer. Wire-array solar cells without some or all of these design features were also fabricated to demonstrate the importance of the light-trapping elements in achieving a high J_(sc). Scanning photocurrent microscopy images of the microwire-array solar cells revealed that the higher J_(sc) of the most advanced cell design resulted from an increased absorption of light incident in the space between the wires. Spectral response measurements further revealed that solar cells with light-trapping elements exhibited improved red and infrared response, as compared to solar cells without light-trapping elements.
Additional Information
© 2010 The Royal Society of Chemistry. Received 5th April 2010, Accepted 18th May 2010. This work was supported by BP and in part by the Department of Energy (Basic Energy Sciences, Energy Frontier Research Center under grant DE-SC0001293 and also grant DE-FG02-07ER46405) and made use of facilities supported by the Caltech Center for Sustainable Energy Research, the Center for Science and Engineering of Materials—an NSF Materials Research Science and Engineering Center at Caltech (DMR 0520565), the Molecular Materials Research Center of the Beckman Institute at Caltech, and the Kavli Nanoscience Institute at Caltech. S.W.B. acknowledges the Kavli Nanoscience Institute for fellowship support, and D.B.T.-E. acknowledges the National Science Foundation for fellowship support. The authors acknowledge Dr Michael Walter for helpful discussions.Attached Files
Published - Putnam2010p11115Energ_Environ_Sci.pdf
Supplemental Material - C0EE00014K.pdf
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Additional details
- Eprint ID
- 19587
- Resolver ID
- CaltechAUTHORS:20100823-105710525
- BP
- Department of Energy (DOE)
- DE-SC0001293
- Department of Energy
- DE-FG02-07ER46405
- Caltech Center for Sustainable Energy Research
- NSF
- DMR-0520565
- Kavli Nanoscience Institute
- NSF Graduate Research Fellowship
- Created
-
2010-08-23Created from EPrint's datestamp field
- Updated
-
2021-11-08Created from EPrint's last_modified field
- Caltech groups
- Kavli Nanoscience Institute