Photocurrent And Noise Analysis as Alternative Approaches to Understanding OFET Behavior

ChEMS Seminar

Speaker: Dr. John Kymissis

Electrical Engineering department

Columbia University


The characterization of organic field effect transistors is

complicated by the influence of the contacts on channel behavior and

the trap limited conduction mechanism which governs device


In this presentation, several strategies for probing OFETs will be

discussed.  In particular, the use of spectrally resolved photocurrent

spectroscopy will be demonstrated as a strategy for the analysis of

trap states in the device, spatially resolved photocurrent will be

presented as an approach for measuring internal device potential, and

noise spectroscopy will be  presented as an approach to evaluating the

effect of trap states on channel conduction.   These probes provide

additional pathways for analyzing OFET device and material behavior

with different complicating parasitics than incumbent characterization


The applications of OFETs, including their utility in instrumenting

electroactive polymers, will also be discussed.


Ioannis (John) graduated with his SB, M.Eng., and Ph.D. degrees from

MIT. His M.Eng. thesis was performed as a co-op at the IBM TJ Watson

Research Lab on organic thin film transistors, and his Ph.D. was in

the Microsystems Technology Lab at MIT working on field emission

displays. After graduation he worked as a post-doc in MIT's

Laboratory for Organic Optics and Electronics working on a variety of

organic electronic devices and as a consulting engineer for QDVision,

which is developing and commercializing a novel light emitting

architecture based on quantum dots.  In 2006, John joined the

Electrical Engineering department at Columbia University and leads the

Columbia Laboratory for Unconventional Electronics (CLUE) which

focuses on the development and applications of thin film electronic