Lloyd Bumm

Associate Professor

bumm

Awards

Nancy Mergler Undergraduate Research Mentor Award

Patent and Innovation

Patent and Innovation

NSF Career Award

 

Education

B.S. 1982 Clarkson University

Ph.D. 1991 Northwestern University

 

Contact

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Ph: (405) 325-6053

Office: 123 Nielsen Hall

 

Home Page

 

Research Description

I am interested in surface physics at the nanometer-scale in condensed systems. In practical terms, can I build an electronic device out of a single molecule? Insight into critical technological problems, such as molecular-scale electronics, molecular light-emitting diodes, and light harvesting systems, relies on understanding fundamental physical processes at the nanometer scale. When a single molecule is placed between two electrodes, what is its electrical conductivity? How does light modify the molecule's electrical properties?

My focus is to understand the electronic and the optoelectronic characteristics of individual molecules and functional nanometer-scale assemblies. The experimental approach is to combine the molecular-scale resolution of scanning probe techniques, such as scanning tunneling microscopy (STM) and atomic force microscopy (AFM), with optical spectroscopy.

We use self-assembled monolayers (SAMs) as a matrix platform in which other molecules can be tethered. SAMs have the advantage that they can be easily prepared under bench-top conditions and their molecular components can be readily imaged by STM. Our recent work has concentrated on developing methods for natural patterning of SAMs on the nanometer scale, including surface-structure directed chemistry. We have a strong collaboration with Ron Halterman's synthetic organic group in chemistry to make the unique molecules used for our work. We have also developed flat gold nanoparticles (FGNPs) as plasmonic substrates for our STM studies. In addition to STM, my group also has developed capability in single nanoparticle spectroscopy for molecular plasmonics and in grazing angle-infrared spectroscopy for SAM characterization. Our group is also interested in developing novel scanning probe techniques.

Selected Publications

"The role of defects and surface states in the carrier transport and non-linearity of the diode characteristics in PbS/ZnO quantum dot solar cells," Y. Cheng; M.C.D. Whitaker, R. Makkia, S. Cocklin, V.R. Whiteside, L.A. Bumm, E. Adcock-Smith, K.P. Roberts, P. Hari, I.R. Sellers, ACS Applied Materials & Interfaces, 9(15), 13269-13277, (2017) DOI: 10.1021/acsami.7b00141

"Real-space post-processing correction of thermal drift and piezoelectric actuator nonlinearities in scanning tunneling microscope images," M. P. Yothers, A. E. Browder and L. A. Bumm, Review of Scientific Instruments, 88(1), 013708, (2017) DOI: 10.1063/1.4974271

"Metal-Enhanced Fluorescence of Dye-Doped Silica Nano Particles," K.B. Gunawardana, N.S. Green, L.A. Bumm and R.L. Halterman, Journal of Fluorescence, 25(2), 311-317, (2015) DOI: 10.1007/s10895-015-1510-8

"Scorpion fluorescence and reaction to light," D.D. Gaffin, L.A. Bumm, M.S. Taylor, N.V. Popokina, S. Mann, Animal Behaviour, 83(2), 429-436, (2012) DOI: 10.1016/j.anbehav.2011.11.014

"Molecularly-Ordered Decanethiol Self-Assembled Monolayers on Au(111) from in-situ-Cleaved Decanethioacetate: An NMR and STM study of the efficacy of reagents for thioacetate cleavage," A. Singh, D.H. Dahanayaka, A. Biswas, L.A. Bumm, R.L. Halterman, Langmuir, 26(16), 13221-13226, (2010) DOI: 10.1021/la100103k

"Measuring Molecular Junctions: What is the standard?," L.A. Bumm, ACS Nano, 2(3), 403-407, (2008) DOI: 10.1021/nn8001246

"Near-field spectroscopy of surface plasmons in flat gold nanoparticles," M. Achermann, K.L. Shuford, G.C. Schatz, D.H. Dahanayaka, L.A. Bumm, V.I. Klimov, Optics Letters, 32(15), 2254-2256, (2007) DOI: 10.1364/OL.32.002254

See more publications.

Research Group

Som Bhattacharya, Graduate Student
Mitchell Yothers, Graduate Student