Quantum-dot-sensitised solar cells

Figure 3.109 Principle of operation of the quantum-dot-sensitised solar cell (QDSSC). Charge injection from excited CdSe QDs into Ti02 nanoparticles (a) is followed by collection of charges at the electrode surface (b). The redox electrolyte e.g. sulfide/polysulfide) scavenges the holes and thus ensures regeneration of the CdSe. Reprinted with permission from Kamat, 2008. Copyright (2008) American Chemical Society...

Quantum dot-sensitised nano crystalline Ti02 solar cells... 

Gary Hodes received his BSc and PhD from Queen s University of Belfast in 1968 and 1971 respectively, and has been at the Weizmann Institute of Science, Rehovot, Israel since 1972. His research has focused on semiconductor film deposition from solutions (initially electrochemical and later chemical bath deposition) and on various types of solar cells (liquid junction, thin film, polycrystalline and nanoporous) and quantum dots using these films. Throughout his career, he has also studied various aspects of semiconductor surface treatments. More recently, he is continuing work on various aspects of chemical bath deposition mechanisms and also increasingly concentrating on nanocrystalline, semiconductor-sensitised solar cells. 

Nanocrystalline semiconductor quantum dots have attracted attention primarily as sensitisers in solar cells, but have also been used as luminescent probes in biological systems, despite concerns over their toxicity (especially with quantum dots containing heavy metals such as Cd and Pb). The recombination of excitons post-excitation can lead to radiative emission with wavelengths shorter than that of the band gap of the bulk semiconductor due to perturbation of the exciton wave-function - so-called quantum confinement effects - at distances shorter than the exciton Bohr radius. For the popular semiconductor cadmium... 

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