Research Overview

Our group works in the area of Organic Electronics, primarily focused on the science needed to  understand and apply easily processed conjugated polymer semiconductors to lighting and biomolecular imaging. We study the science of light emission, charge photogeneration and recombination that underpins future applications of polymers in flexible displays, solid state lighting and biomolecular sensing/imaging. The techniques we use span the range from transient spectroscopy of excited state relaxation to confocal fluorescence microscopy to charge modulation spectroscopy in devices. Our current collaborators in the Organic Electronics area are Al Marchetti and Ralph Young (Chemistry), Alex Shestopalov and Ching Tang (Chemical Engineering), Linda Peteanu (Carnegie Mellon), Marina Kondakova (OLEDWorks LLC) and Bin Liu (National University of Singapore). Recent accomplishments include single chain studies of conjugated polymers, mechanistic studies of thermally activated delayed fluorescent materials, magnetic field effects on charge recombination and plasmonic enhancement of organic photovoltaics. 

Research Interests

• Polymer electronics
• optoelectronic devices
• light-emitting diodes
• thin-film transistors
• photodetectors
• xerographic photoreceptors
• biological sensors
• electrooptic modulators

Selected Publications

• “Role of Aggregates in the Luminescence Decay Dynamics of Conjugated Polymers”, R. Chakraborty and L.J. Rothberg, J. Phys. Chem. A 2016, 120, 551-555.  
• “High efficiency phosphorescent white organic light-emitting diodes with an ultra-thin red and green co-doped layer and dual blue emitting layers”, L.S. Xu, C.W. Tang and L.J. Rothberg, Organic Electronics  2016, 32, 54-58. 
• “Plasmon-Enhanced Photoconductivity in Amorphous Silicon Thin Films by use of Thermally Stable Silica-Coated Gold Nanorods”, C.-S. Chang and L.J. Rothberg, Chem. Mater. 2015, 27, 3211-3215. 
• “Plasmonic effects of Ag nanoparticles studied with freestanding thin-film amorphous silicon solar cells”, J.D. Winans, C. Hungerford, K. Shome, L.J. Rothberg and P.M. Fauchet, Opt. Express 2015, 23, A92-A105.
• “Investigating blue phosphorescent iridium cyclometalated dopant with phenyl-imidazole ligands”, K.P. Klubek, S.C. Dong, L.S. Liao, C.W. Tang and L.J. Rothberg, Organic Electronics 2014, 15, 3127 – 3136.
• “Permanent polarization and charge distribution in organic light-emitting diodes: insights from near-infrared charge modulation spectroscopy of an operating OLED”, A.P. Marchetti, T.L. Haskins, R.H. Young and L.J. Rothberg J. Appl. Phys. 2014, article 114506. 
• “Investigation of blue phosphorescent organic light emitting diode host  and dopant stability”, K.P. Klubek, C.W. Tang and L.J. Rothberg, Organic Electronics 2014, 15, 1312 – 1316.