Thermodynamic efficiency limit of excitonic solar cells
Open Access
- 31 May 2011
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 83 (19)
- https://doi.org/10.1103/physrevb.83.195326
Abstract
Excitonic solar cells, comprised of materials such as organic semiconductors, inorganic colloidal quantum dots, and carbon nanotubes, are fundamentally different than crystalline, inorganic solar cells in that photogeneration of free charge occurs through intermediate, bound exciton states. Here, we show that the Second Law of Thermodynamics limits the maximum efficiency of excitonic solar cells below the maximum of 31% established by Shockley and Queisser [J. Appl. Phys. 32, 510 (1961)] for inorganic solar cells (whose exciton-binding energy is small). In the case of ideal heterojunction excitonic cells, the free energy for charge transfer at the interface, Δ, places an additional constraint on the limiting efficiency due to a fundamental increase in the recombination rate, with typical −Δ in the range 0.3 to 0.5 eV decreasing the maximum efficiency to 27% and 22%, respectively. DOI: http://dx.doi.org/10.1103/PhysRevB.83.195326 ©2011 American Physical Society
Keywords
This publication has 24 references indexed in Scilit:
- The Energy of Charge‐Transfer States in Electron Donor–Acceptor Blends: Insight into the Energy Losses in Organic Solar CellsAdvanced Functional Materials, 2009
- Molecular and Morphological Influences on the Open Circuit Voltages of Organic Photovoltaic DevicesJournal of the American Chemical Society, 2009
- Analytical model for the open-circuit voltage and its associated resistance in organic planar heterojunction solar cellsPhysical Review B, 2008
- Offset energies at organic semiconductor heterojunctions and their influence on the open-circuit voltage of thin-film solar cellsPhysical Review B, 2007
- Excitons in nanoscale systemsNature Materials, 2006
- Design Rules for Donors in Bulk‐Heterojunction Solar Cells—Towards 10 % Energy‐Conversion EfficiencyAdvanced Materials, 2006
- The Photoconversion Mechanism of Excitonic Solar CellsMRS Bulletin, 2005
- Entropy production in photovoltaic conversionPhysical Review B, 1997
- The chemical potential of radiationJournal of Physics C: Solid State Physics, 1982
- Photon-Radiative Recombination of Electrons and Holes in GermaniumPhysical Review B, 1954