1. Transparent and Flexible Electronics


Next generation high performance display devices require new materials that present high carrier mobility, excellent stability over time, and low cost-procesability.  We focus on the development of new types of materials including transition-metal oxides, conjugated polymers, and the fabrication of thin film transistors (TFTs) for the potential applications in high-performance active matrix displays.



Recent Papers: 
- S. Lee, D. Borrelli, and K Gleason, “Air-stable polythiphene-based thin film transistors processed using oxidative chemical vapor deposition: carrier transport and channel/metallization contact interface” Organic Electronics, 33, 253-262 (2016)
- S. Lee, and D. Paine, “Metallization selection and the performance of amorphous In-Zn-O thin film transistors” Applied Physics Letters, 104, 252103 (2014)
- S. Lee†, D. Borrelli†, and K. Gleason, “Optoelectronic properties of polythiophene thin films and organic TFTs fabricated by oxidative chemical vapor deposition” Journal of Materials Chemistry C, 2, 7223-7231 (2014)
[†] equal contribution

2. Materials for Energy Conversion Devices

There is a clear and urgent need for the development of new- and/or renewable energy technologies.  Our research interests lie in materials processing using novel synthesis techniques (e.g., oxidative CVD, extremely low oxygen pressure annealing) and uncovering their physical properties for energy conversion device applications (e.g., Solar cells, Fuel cells). 









Recent Papers:

- H. Kim, *S. Lee, S. Kim, C. Oh, J. Ryu, J. Kim, E. Park, S. Hong and K. No, “Enhanced ethanol-crossover by the incorporation of phosphotungstic acid in Nafion membrane for direct ethanol fuel cells” submitted (2016)
- S. Lee, X. Guan, and S. Ramanathan, “Synthesis of thin film oxy-apatites and solid state fuel cells” Journal of the Electrochemical Society 163, F719-F727 (2016)
- N. Chen, P. Kovacik, R. Howden, S. Lee, and K. Gleason, “Low-substrate-temperature Encapsulation for Flexible Electrodes and Organic Photovoltaics” Advanced Energy Materials, 5,  1401442 (2015)

3. Novel Materials Processing

Oxidative Chemical-Vapor-Deposition (oCVD) is a unique solvent-free polymer coating technique that offers a simple and easy approach to synthesizing and depositing conjugated polymers irrespective of polymer solubility or the properties of the substrate material, unlike solvent-involving processes or electrochemical polymerization.  The oCVD method has the merits of excellent film uniformity over large areas, high electrical conductivity, conformal coating on non-planar substrates (e.g., textiles and trenches), and low process temperature (20-100 °C), along with scalability for roll-to-roll mass production.



Recent Papers:

- S. Lee, K. Gleason, “Enhanced optical property with tunable band gap of cross-linked amorphous PEDOT copolymers via oxidative chemical vapor deposition” Advanced Functional Materials, 25, 85-93 (2015)
- S. Lee, D. Paine, and K. Gleason, “Heavily doped poly(3,4-ethylenedioxythiophene) thin films with high carrier mobility deposited using oxidative CVD: conductivity stability and carrier transport” Advanced Functional Materials, 24, 7187–7196 (2014)  
- A. Coclite, R. Howden, D. Borrelli, S. Lee, and K. Gleason et al., “CVD Polymers: A new paradigm for surface modification and device fabrication” Advanced Materials, 25, 5392 (2013)

4. Microstructure Analysis

The evolution of microstructure and the phase transformation of materials as a function of processing conditions are being studied in a wide range of materials synthesized by physical vapor deposition and chemical vapor deposition techniques.


Recent Papers:

- S. Lee, X. Guan, and S. Ramanathan, “Synthesis of thin film oxy-apatites and solid state fuel cells” Journal of the Electrochemical Society 163, F719-F727 (2016)

- S. Lee, K. Park, and D. Paine, "Metallization Strategies for In2O3-based amorphous oxide semiconductor materials" Jornal of Materials Research 27, 2299-2308 (2012)