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Garry Rumbles — Research Fellow

Photo of Garry Rumbles.

Dr. Garry Rumbles is a Research Fellow at the National Renewable Energy Laboratory (NREL). Dr. Rumbles joined NREL in 2000 and is widely recognized for his research in photochemistry and photophysics of conjugated molecular systems, energy conversion in organic light emitting diodes and organic photovoltaic devices, and nanoscale morphology. In May 2009, he became a Professor Adjoint in the Department of Chemistry and Biochemistry at CU Boulder; and in October 2009 a Fellow of the joint CU/NREL adventure: Renewable and Sustainable Energy Institute (RASEI). In 2004, he was made a Fellow of the Royal Society of Chemistry. Dr. Rumbles has published more than 130 journal articles and more than 10 book sections.

Research Areas

Dr. Rumbles' current research interests are in solar energy with a focus on the basic science of solar photoconversion processes and photoinduced electron transfer processes in polymer-based nanostructured interfaces. However, his primary research expertise lies in photochemistry and photophysics, with a specialty in kinetics. Over the past 25 years, he has conducted a wide range of studies that investigate: excited-state kinetics in synthetic polymers; cis-trans isomerization of natural chromophores in biomolecules; spectroscopy of transient, gas-phase molecules; photophysics at solid-solution interfaces; third-order nonlinear optical properties of conjugated molecules; frequency upconversion and optical refrigeration in dye solutions; and the fundamental photophysics of conjugated (electroluminescent) polymers, colloidal quantum dots, and single-walled carbon nanotubes (SWNTs).

He has experience with a variety of laser-based experiments that include: time-resolved fluorescence spectroscopy; time-resolved resonance Raman spectroscopy; laser-induced fluorescence spectroscopy; time-resolved evanescent wave-induced fluorescence spectroscopy; picosecond coherent anti-Stokes Raman spectroscopy; transient absorption spectroscopy; and time-resolved microwave conductivity.

He has a strong association with NREL's organic photovoltaic research team, which provides an avenue to explore some of the more applied solar energy problems. Currently, Dr. Rumbles is using time-resolved microwave conductivity (TRMC) as a tool for studying the dissociation and recombination kinetics of nanoscale excitons at interfaces formed between molecular-based species. In this work, TRMC is an ideal tool for following not only the loss of photoexcited excitons in, for example, a conjugated polymer, but also the formation of charged, free carriers when the polymer is at an interface with an acceptor such as a C60, a SWNT, or a colloidal quantum dot. Such interfaces are the primary requirement for constructing an organic photovoltaic device, but these studies also provide a valuable insight into the fundamental light-harvesting process that allows the devices to function.

Professional Experience

Dr. Garry Rumbles conducted his Ph.D. research under the supervision of Professor David Phillips in the Davy Faraday Research Laboratory (DFRL) at the Royal Institution in London. He spent more than three years as a postdoctoral researcher — first at the University of Arizona with Professor George Atkinson, and then at the University of California, Irvine, with the late Professor Edward K.C. Lee.

Dr. Rumbles returned to the DFRL in 1987; in 1989, he became a lecturer in Physical Chemistry in the Department of Chemistry at Imperial College. He was promoted to senior lecturer in 1996 and reader in 2001. During his tenure at Imperial College, Dr. Rumbles graduated 12 Ph.D. students and received two Imperial College awards for excellence in teaching.

Dr. Rumbles joined NREL as a sabbatical scientist in 2000, working with Dr. Arthur Nozik, and in 2001 became a Senior Research Scientist. He retained his affiliation with Imperial College through the award of a visiting professorial chair, a position that he still holds, and he is a member of the Chemistry Department's Advisory Board.

In 2005, Dr. Rumbles was promoted to Principal Scientist at NREL and became the group manager of the Chemical and Nanoscale Science team within the Center for Basic Sciences, and subsequently within the Chemical and Biosciences Center. In 2008, he was named an NREL Research Fellow. He is a Fellow of the Royal Society of Chemistry and a member of the American Chemical Society. He has close to 130 research publications and has an H-index of 27.


  • Ph.D. in Photophysics of Synthetic Polymers awarded by the University of London, 1984
  • B.S. in Chemistry with Electronics awarded by University of Southampton, 1980

NREL Publications

View all NREL Publications for this staff member.