Hostname: page-component-8448b6f56d-qsmjn Total loading time: 0 Render date: 2024-04-25T02:06:02.287Z Has data issue: false hasContentIssue false

Effects of Inserting Highly Polar Salts Between the Cathode and Active Layer of Bulk Heterojunction Photovoltaic Devices

Published online by Cambridge University Press:  21 March 2011

Sean E. Shaheen
Affiliation:
Optical Sciences Center, University of Arizona, Tucson, AZ 85721, USA
Christoph J. Brabec
Affiliation:
Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University of Linz, A-4040 Linz, Austria
N. Serdar Sariciftci
Affiliation:
Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University of Linz, A-4040 Linz, Austria
Ghassan E. Jabbour
Affiliation:
Optical Sciences Center, University of Arizona, Tucson, AZ 85721, USA
Get access

Abstract

Thermal deposition of small amounts of various salts at the interface between the active layer and the aluminum cathode was shown to alter the performance of bulk heterojunction photovoltaic devices. LiF and LiBr were found to enhance the power conversion efficiency as compared to devices with no interfacial salt, but Cs and K compounds were found to severely diminish the device performance. It is suggested that the Li compounds preferentially align to produce a bulk dipole moment at the interface, whereas the Cs and K compounds do not.

Type
Research Article
Copyright
Copyright © Materials Research Society 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Sariciftci, N. S., Smilowitz, L., Heeger, A. J., and Wudl, F., Science 258, 1474 (1992).Google Scholar
2. Yu, G., Gao, J., Hummelen, J. C., Wudl, F., and Heeger, A. J., Science 270, 1789 (1995).Google Scholar
3. Shaheen, S. E., Brabec, C. J., Sariciftci, N. S., Padinger, F., Fromherz, T., ad Hummelen, J. C., Appl. Phys. Lett.z 78, 841 (2001).Google Scholar
4. The power conversion efficiency η of a photovoltaic device, under illuminaton by a source of arbitary spectrum and intensity, is given by where Pout is the output electrical power of the device under illumination, Pin is the light intensity incident on the device, VOC is the open-circuit voltage, and JSC is the short-circuit current density. FF is the fill factor, given by where Vmpp and Jmpp are the voltage and current density at the maximum power point, respectively.Google Scholar
5. Hung, L. S., Tang, C. W., and Mason, M. G., Appl. Phys. Lett. 70, 152 (1997).Google Scholar
6. Jabbour, G. E., Kawabe, Y., Shaheen, S. E., Wang, J. F., Morrell, M. M., Kippelen, B., and Peyghambarian, N., Appl. Phys. Lett. 71,1762 (1997).Google Scholar
7. Shaheen, S. E., Jabbour, G. E., Morrell, M. M., Kawabe, Y., Kippelen, B., Peyghambarian, N., Nabor, M. F., Schlaf, R., Mash, E. A., and Armstrong, N. R., J. Appl. Phys. 84, 2324 (1998).Google Scholar
8. Yoon, J., Kim, J.-J., Lee, T.-W., and Park, O.-O., Appl. Phys. Lett. 76, 2152 (2000).Google Scholar
9. Brown, T. M., Friend, R. H., Millard, I. S., Lacey, D. J., Burroughes, J. H., Cacialli, F., Appl. Phys. Lett. 77, 3096 (2000).Google Scholar
10. Ishii, H., Sugiyama, K., Ito, E., and Seki, K., Adv. Mater. 8, 605 (1999).Google Scholar
11. Heil, H., Steiger, J., Karg, S., Gastel, M., Ortner, H., Seggern, H. von, Stäßel, M., J. Appl. Phys. 89, 420 (2001).Google Scholar
12. Jabbour, G. E., Kippelen, B., Armstrong, N. R., Peyghambarian, N., Appl. Phys. Lett. 73, 1185 (1998).Google Scholar
13. Unpublished results.Google Scholar