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Increasing Efficiency with Multiple Exciton Generation

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Quantum Dot Solar Cells

Part of the book series: Lecture Notes in Nanoscale Science and Technology ((LNNST,volume 15))

Abstract

In a conventional solar cell the energy of an absorbed photon in excess of the band gap is lost as heat as the photo-generated charges cool rapidly to the band edge; for a silicon-based cell under standard insolation this loss is equivalent to 47 % of incident power. However, in colloidal quantum dots an alternative process can become significant—multiple exciton generation (MEG). Here, immediately after the absorption of a photon photo-generated carriers can instead use this excess energy to produce additional electron–hole pairs, which can contribute to the photocurrent and thereby increase the efficiency of a solar cell. In this chapter, this phenomenon will be introduced and its potential for increasing the efficiency of quantum dot solar cells discussed. MEG was first investigated spectroscopically and the challenging techniques used will be described. Progress since the first demonstration of MEG in 2004 will then be reviewed, including the controversy over quantum yields and its resolution. The recent demonstration of devices benefiting from MEG will be detailed. Finally, several possible future directions for research will be discussed.

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Authors and Affiliations

  1. School of Physics and Astronomy & Photon Science Institute, University of Manchester, Manchester, M13 9PL, UK

    N. McElroy, M. Cadirci, A. Al-Otaify, R. Page & D. J. Binks

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  1. N. McElroy
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  2. M. Cadirci
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  3. A. Al-Otaify
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  4. R. Page
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  5. D. J. Binks
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Correspondence to D. J. Binks .

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Editors and Affiliations

  1. State Key Laboratory of Electronic Thin, University of Electronic Science and Technology of China, Chengdu, China, People's Republic

    Jiang Wu

  2. State Key Laboratory of Electronic, University of Electronic Science and Technology, Chengdu, China, People's Republic

    Zhiming M. Wang

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McElroy, N., Cadirci, M., Al-Otaify, A., Page, R., Binks, D.J. (2014). Increasing Efficiency with Multiple Exciton Generation. In: Wu, J., Wang, Z. (eds) Quantum Dot Solar Cells. Lecture Notes in Nanoscale Science and Technology, vol 15. Springer, New York, NY. https://doi.org/10.1007/978-1-4614-8148-5_9

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  • DOI: https://doi.org/10.1007/978-1-4614-8148-5_9

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