Professor Dick T. Co

Northwestern University
2190 Campus Drive
Evanston, IL 60208-3113

E-mail:
co[at]northwestern.edu

2010-present
Research Assistant Professor of Chemistry
Northwestern University
Argonne-Northwestern Solar Energy Research (ANSER) Center

Fellowships & Awards | Research Interests | Publications | Group Home

Fellowships and Awards

  • Camille and Henry Dreyfus Environmental Chemistry Mentor (2010)
  • Fellow, Chemistry Communication Leadership Institute, Univ. of Washington (2009) Sponsored by the National Science Foundation and American Chemical Society
  • National Science Foundation Graduate Research Fellowship (2003-2006)
  • Certificate of Distinction for Excellence in Teaching, Harvard University (2004)
  • Robert Karplus Prize in Chemical Physics, Harvard University (2002)
  • Outstanding Instructor Award, UC Berkeley (2002)
  • Departmental Citation for Undergraduate Excellence in Chemistry, UC Berkeley (2002) Awarded to the top graduating senior in the major for “unusual talent and promise”
  • Commencement Speaker, UC Berkeley (2002)
  • Phi Beta Kappa (elected 2002)
  • Nathan and Violet David Research Scholarship, UC Berkeley (2000-2002)

 

Education

2002-2007
Ph.D. in Chemical Physics, Harvard University
Advisor: James G. Anderson
Thesis title: “Development of a Laser-Induced Fluorescence Instrument for the in Situ Atmospheric Measurements of Iodine Monoxide”
A.M. in Chemistry and Chemical Biology

1998-2002
B.S. with High Honors in Chemistry, University of California, Berkeley
Advisor: Richard J. Saykally

Research Interests

Global energy needs are projected to double by 2050 and triple by 2100, and continual reliance on carbon-based fuels is simply not environmentally sustainable.  The irreversibility of atmospheric dynamics and photochemistry due to CO2 forcing calls for immediate actions to develop secure, clean, and sustainable energy.  An increase in the use of solar energy, by far the largest renewable source, is thus essential for meeting this need in an environmentally responsible manner.

I. Femtosecond Stimulated Raman Spectroscopy (Solar Energy Research)

Using femtosecond stimulated Raman spectroscopy (FSRS), our team is investigating the ultrafast structural dynamics of interfacial photoinduced electron transfer (PET) reactions in hybrid semiconductor quantum dots (QDs).

FSRS is an ultrafast spectroscopic technique that produces high-quality atomic structural information simultaneously with high temporal resolution (< 100 fs).  Unique advantages of utilizing QDs in solar cells are that the energy gap can be modulated by changing the material and size, and that multiple excitons can be generated upon photoexcitation.  However, in order for QDs to be viable for applications in photovoltaic devices, extraction of photoexcited charge carriers from the QDs needs to be competitive with ultrafast excitonic relaxation.  One promising approach to overcome this challenge is through interfacial PET, yet the molecular mechanisms of PET in heterogeneous QDs remain largely elusive.  In such non-thermalized systems, postexcitation vibrational modes are expected to play significant roles in mediating electron transfer pathways, and localization of the electron(s) or hole(s) can affect the efficiency of unwanted back electron transfer reactions.

Our work is expected to build a new knowledge base of how the structural dynamics of the adsorbed ligands affect the mechanisms, rates, yield, and multiplicity of interfacial PET in semiconductor QD systems.  The goal is to develop functionalized QDs that can make effective use of multiple excitons and ultimately be utilized in solar cells or photocatalytic nanosystems.

I gratefully acknowledge support from the Dreyfus Foundation and the Initiative for Sustainability and Energy at Northwestern (ISEN).

II. Science Communication and Outreach

A recent Northwestern study led by Ellen Wartella at the Center on Media and Human Development has shown that minority youth today are consuming media content at once unfathomable amounts: an average of 9 – 13 hours per day!

How we educators learned yesterday is simply not the same way as how students are learning today.  Science education needs to evolve with the digital age.

To that end, I have initiated a program at Northwestern, in collaboration with Untamed Science, a non-profit science education organization, to launch Untamed Chemistry. This online comprehensive educational program targets America’s school audience (primarily high school) using an array of student-engaging multimedia. With over 200 videos covering every science category from K-12, Untamed Science videos will be viewed by over 50% of the science students in America over the next decade.

My goal is to connect Northwestern’s existing leadership in solar energy research, material science, and engineering to an established national distribution channel of online educational media to maximize our impact and reach with traditionally underrepresented groups in STEM fields.  By offering exciting outlooks to chemistry research and careers in the students’ language, I hope to provide a spark for students to delve deeper into the subject matter and explore their world.

I am also developing a novel digital textbook on the iPad platform that will allow us to embed 3D structures that students can manipulate, interactive graphics and galleries, aforementioned videos, self-playing presentations, and most excitingly, web-based dynamically updated data to include latest cutting-edge research from Northwestern. Discoveries in solar energy research, for example, happen at a very rapid pace. Thus, by linking the textbook content to the latest research results and solar cell performance at Northwestern and other institutions as well, students can have the most up-to-date data and numbers.

Funding for the outreach projects are generously provided by the Initiative for Sustainability and Energy at Northwestern (ISEN) and the Alumnae of Northwestern University.

Publications

Ultrafast Photodriven Intramolecular Electron Transfer from an Iridium-Based Water-Oxidation Catalyst to Perylene Diimide Derivatives, M. T. Vagnini, A. L. Smeigh, J. D. Blakemore, S. W. Eaton, N. D. Schley, F. D’Souza, R. H. Crabtree, G. W. Brudvig, D. T. Co, and M. R. Wasielewski, Proc. Natl. Acad. Sci. USA (doi: 10.1073/pnas.1202075109)
     
Direct Observations of Nanoparticle-Cancer Cell Nucleus Interactions, D. H. M. Dam, J. H. Lee, P. N. Sisco, D. T. Co, M. Zhang, M. R. Wasielewski, and T. W. Odom, ACS Nano, 6, 3318-3326 (2012)
     
Intersystem Crossing Involving Strongly Spin Exchange-Coupled Radical Ion Pairs In Donor-Bridge-Acceptor Molecules, M. T. Colvin, A. Butler Ricks, A. M. Scott, D. T. Co, and M. R. Wasielewski, J. Phys. Chem A, 116, 1923-1930 (2012)

Exponential Distance Dependence of Photoinitiated Stepwise Electron Transfer in Donor-Bridge-Acceptor Molecules: Implication for Wire-like Behavior, A. Butler Ricks, K. E. Brown, M. Wenninger, S. D. Karlen, Y. A. Berlin, and D.T. Co, M. R. Wasielewski, J. Am. Chem. Soc., 134, 4581-4588  (2012)

Electron Transfer Within Self-Assembling Cyclic Tetramers Using Chlorophyll-Based Donor-Acceptor Building Blocks, V. L. Gunderson, C. H. Kim, A. L. Smeigh, D. T. Co, and M. R. Wasielewski, J. Am. Chem. Soc., 134, 4363-4372 (2012)

Photoinduced Multistep Charge Separation in Ferrocene-Zinc Porphyrin Hydrogenase Model Complex Triads, P. Poddutoori, D. T. Co, A. P. S. Samuel, C. H. Kim, M. T. Vagnini, and M. R. Wasielewski, Energy Environ. Sci., 4, 2441-2450(2011)

Scientists Turn to Nature for Clues on Building Better Fuel Cells, D. T. Co, Northwest Science & Technology News Spring Issue (2010)

Ultrafast Photodriven Intramolecular Electron Transfer from a Zinc Porphyrin to a Readily-Reduced Diiron Hydrogenase Model Complex, A. P. S. Samuel, D. T. Co, C. L. Stern, and M. R. Wasielewski, J. Am. Chem. Soc. 132, 8813-8815 (2010)

Narrow-Bandwidth Tunable Picosecond Pulses in the Visible Produced by Noncollinear Optical Parametric Amplification with a Chirped Blue Pump, D. T. Co, J. V. Lockard, D. W. McCamant, and M. R. Wasielewski, Appl. Opt. 49, 1880-1885 (2010)

Photophysics and Redox Properties of Rylene Imide and Diimide Dyes Alkylated Ortho to the Imide Groups, J. E. Bullock, M. T. Vagnini, C. Ramanan, D. T. Co, T. W. Wilson, J. W. Dicke, T. J. Marks, and M. R. Wasielewski, J. Phys. Chem. B 114, 1794-1802 (2010)

Interrogating the Intramolecular Charge-Transfer State of a Julolidine-Anthracene Dono-Acceptor Molecule with Femtosecond Stimulated Raman Spectroscopy, J. V. Lockard, A. B. Ricks, D. T. Co, and M. R. Wasielewski, J. Phys. Chem. Lett. 1, 215-218 (2010)

Rotationally Resolved Absorption Cross Sections of Formaldehyde in the 28100-28500 cm-1 (351-356 nm) Spectral Region: Implications for In Situ LIF Measurements, D. T. Co, T. F. Hanisco, J. G. Anderson, and F. N. Keutsch, J. Phys. Chem. A 109, 10675-10682 (2005)

Investigation of Volatile Liquid Surfaces by Synchrotron X-ray Spectroscopy of Liquid Microjets, K. R. Wilson, B. S. Rude, J. Smith, C. Cappa, D. T. Co, R. D. Schaller, M. Larsson, T. Catalano, and R. J. Saykally, Rev. Sci. Instrum. 75, 725-736 (2004)

Surface Relaxation in Liquid Water and Methanol Studied by X-ray Absorption Spectroscopy, K. R. Wilson, R. D. Schaller, D. T. Co, R. J. Saykally, B. S. Rude, T. Catalano, and J. D. Bozek, J. Chem. Phys. 117, 7738-7734 (2002)

X-ray Spectroscopy of Liquid Water Microjets, K. R. Wilson, B. S. Rude, T. Catalano, R. D. Schaller, J. G. Tobin, D. T. Co, and R. J. Saykally, J. Phys. Chem. B 105, 3346-3349 (2001, cover article)