Bardeen Research Group

Department of Chemistry | University of California @ Riverside | 501 Big Springs Road | 127-131 CS-1

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University of California

Bardeen Research Group
University of California, Riverside * Department of Chemistry
501 Big Springs Rd * Riverside, CA 92521, USA
Phone: +1.951.827.2723 * Fax: +1.951.827.4713 * Email:

The goal of our research is to discover new and better ways to control and optimize photoinduced processes in organic materials. Our research involves both the synthesis of new materials and the use of laser spectroscopy and microscopy to study dynamics.

This work has practical applications in
  • the creation of photomechanical nanostructures
  • the conversion of solar energy
  • photoprotection against skin cancer
  • Group Photo

    Nanomolecular Photomechanical Ratchets

    In a spin: Slow pH-driven reprecipitation of 4-fluoroanthracenecarboxylic acid from aqueous solution results in the growth of branched microcrystals. The twisting of the branches under illumination drives a rotation of the overall crystal, as seen by optical microscopy, and can be repeated by repeated pulses of light. In the example shown, an X-shaped molecular crystal undergoes a net clockwise rotation of 50° 

    Photomechanical structures may provide self-assembled nanomachines that could potentially do useful work.

    See Julia, Rabih, & Chris' latest paper: "Photoinduced ratchet-like rotational motion of branched molecular crystals," L. Zhu, R. O. Al-Kaysi, and C. J. Bardeen, Angewandte Chemie, 55, 7073-7076 (2016).



    Reshaping the Solar Spectrum:
    A hybrid molecule combines inorganic semiconductor nanocrystals with organic emitters to "reshape the solar spectrum" so that it better matches the materials used today in solar cells. It works by first capturing two infrared photons that would normally pass right through a solar cell without being converted to electricity, then adds their energies together to make one higher energy photon. This upconverted photon is readily absorbed by photovoltaic cells, generating electricity from light that normally would be wasted.

    Check out our paper Hybrid Molecule-Nanocrystal Photon Upconversion Across the Visible and Near-IR. NanoLetters 2015, 15, 5552-5557 (2015)