Nature of Photovoltaic Action in Dye-Sensitized Solar Cells

David Cahen, Gary Hodes, Michael Grätzel, Jean François Guillemoles, Ilan Riess

Research output: Contribution to journalArticlepeer-review

677 Scopus citations


We explain the cause for the photocurrent and photovoltage in nanocrystalline, mesoporous dye-sensitized solar cells, in terms of the separation, recombination, and transport of electronic charge as well as in terms of electron energetics. On the basis of available experimental data, we confirm that the basic cause for the photovoltage is the change in the electron concentration in the nanocrystalline electron conductor that results from photoinduced charge injection from the dye. The maximum photovoltage is given by the difference in electron energies between the redox level and the bottom of the electron conductor's conduction band, rather than by any difference in electrical potential in the cell, in the dark. Charge separation occurs because of the energetic and entropic driving forces that exist at the dye/electron conductor interface, with charge transport aided by such driving forces at the electron conductor/contact interface. The mesoporosity and nanocrystallinity of the semiconductor are important not only because of the large amount of dye that can be adsorbed on the system's very large surface, but also for two additional reasons: (1) it allows the semiconductor small particles to become almost totally depleted upon immersion in the electrolyte (allowing for large photovoltages), and (2) the proximity of the electrolyte to all particles makes screening of injected electrons, and thus their transport, possible.

Original languageEnglish
Pages (from-to)2053-2059
Number of pages7
JournalJournal of Physical Chemistry B
Issue number9
StatePublished - 9 Mar 2000
Externally publishedYes


Dive into the research topics of 'Nature of Photovoltaic Action in Dye-Sensitized Solar Cells'. Together they form a unique fingerprint.

Cite this