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Infrared photovoltaics made by solution processing

Nature Photonics volume 3, pages 325–331 (2009)Cite this article

Abstract

Solution-processed photovoltaics offer a cost-effective path to harvesting the abundant resource that is solar energy. The organic and polymer semiconductors at the heart of these devices generally absorb only visible light; however, half of the Sun's power reaching the Earth's surface lies in the infrared. Flexible solar cells that harvest wavelengths beyond 1 μm were first reported in 2005. In three years they have increased over 10,000-fold in power conversion efficiency. The latest devices achieve power conversion efficiencies in the infrared of more than 4%, values comparable to those of their organic and polymer counterparts in the visible. Here we review the progress and prospects for the field, focusing on new insights into how quantum-dot solar cells operate and how these findings give guidance on optimizing these devices to their full performance potential.

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Figure 1: The Sun's power spectrum reaching the Earth and its consequences for solar cell design.
Figure 2: Architecture of a typical solution-processed infrared photovoltaic cell.
Figure 3: Progress in infrared monochromatic power conversion efficiency of solution-processed photovoltaics.
Figure 4: Drift and diffusion of charge carriers in photovoltaics.
Figure 5: Spatial band diagram of a colloidal quantum-dot solid.
Figure 6: Breaking the extraction–absorption compromise through nanostructuring.

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Acknowledgements

I thank S. Hinds for producing the spatial band diagrams of Fig. 4.

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  1. Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, M5S 3G4, Ontario, Canada

    Edward H. Sargent

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Sargent, E. Infrared photovoltaics made by solution processing. Nature Photon 3, 325–331 (2009). https://doi.org/10.1038/nphoton.2009.89

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