Abstract
Photon up-conversion (UC) and photon-induced multiple-exciton generation (MEG) are proposed directions that are of increasing interest for improving photovoltaic (PV) conversion efficiencies via "photon (or light) management". Straightforward analysis of these approaches for non-concentrated single-junction cells in the detailed balance limit yields a theoretical PV conversion limit of 49%, instead of 31% without UC and MEG. With what we estimate to be optimistic, maximal realistic efficiencies (25% for UC; 70% for MEG) this limit becomes <40%, i.e., ∼1.25 times the theoretical efficiency of conventional single-band gap cells. While this result does not detract from the fascinating fundamental scientific challenge to make UC and MEG simple and cheap ways to improve PV, such reality checks should be considered when evaluating the short-term promises of these and other options, such as spectral splitting and tandem arrangements.
| Original language | English |
|---|---|
| Pages (from-to) | 1541-1546 |
| Number of pages | 6 |
| Journal | Solar Energy Materials and Solar Cells |
| Volume | 92 |
| Issue number | 12 |
| DOIs | |
| State | Published - Dec 2008 |
| Externally published | Yes |
Bibliographical note
Funding Information:We thank O.M. Stafsudd (UCLA), D. Oron (Weizmann), A. J. Nozik (NREL) and G. Smestad for fruitful discussions, for asking and answering hard questions, even if we do not agree on all the answers. We acknowledge partial support from the Nancy and Stephen Grand Center for Sensors and Security, the Ilse Katz Center for Materials Research, the NATO Science for Peace Program and a research grant from Jack N. Halpern. HS holds an ISF convergent technology predoctoral fellowship. DC holds the Rowland and Sylvia Schaefer Chair in Energy Research.
Funding
We thank O.M. Stafsudd (UCLA), D. Oron (Weizmann), A. J. Nozik (NREL) and G. Smestad for fruitful discussions, for asking and answering hard questions, even if we do not agree on all the answers. We acknowledge partial support from the Nancy and Stephen Grand Center for Sensors and Security, the Ilse Katz Center for Materials Research, the NATO Science for Peace Program and a research grant from Jack N. Halpern. HS holds an ISF convergent technology predoctoral fellowship. DC holds the Rowland and Sylvia Schaefer Chair in Energy Research.
| Funders | Funder number |
|---|---|
| Ilse Katz Center for Materials Research | |
| NATO Science for Peace Program | |
| Nancy and Stephen Grand Center for Sensors and Security |
Keywords
- Down-conversion
- Efficiency
- Multiple-exciton generation
- Photon management
- Up-conversion
