Item Details

abstract

OSCs are becoming an integral part of our lives as active components of various optoelectronic devices given their low-cost processing, light weight, chemical versatility by molecular design, and compatibility with flexible substrates. These systems undergo considerable electronic and structural transformations during device fabrication and operation, which can profoundly impact their performance and stability. Characterization techniques that can elucidate the mechanisms of the time-dependent transformations occurring in these materials and devices are needed to guide the design and processing to yield high-performance and stable devices. In this dissertation, a highly efficient method is introduced to elucidate the microscopic processes occurring within OSCs and electronic devices when deliberately exposed to different external stimuli by accessing in real time, the trap DOS spectrum of the OSC using OFET measurements. In the first study, the method was employed to monitor the generation/annihilation of charge carrier traps in a high-mobility small molecule OSC as a result of microstructural changes occurring in the film during exposure to solvent vapors. Next, we investigate the underlying physical processes impacting the operational stability of OFETs based on small molecules and conjugated polymers. Lastly, we investigate the role of water-related traps in the operation of polymer OFETs. The trap DOS analysis provided an experimental platform to identify several performance limiting processes taking place in OFETs. Consequently, these insights allowed us to devise strategies to consistently achieve high performance devices with exceptional operational and environmental stability.

subject

charge carrier traps

organic semiconductors

contributor

Haneef, Hamna (author)

Jurchescu, Oana (committee chair)

Welker, Mark (committee member)

Holzwarth, Natalie (committee member)

Guthold, Martin (committee member)

Thonhauser, Timo (committee member)

date

2021-06-03T08:35:55Z (accessioned)

2021-12-02T09:30:13Z (available)

2021 (issued)

degree

Physics (discipline)

embargo

2021-12-02 (terms)

identifier

http://hdl.handle.net/10339/98787 (uri)

language

en (iso)

publisher

Wake Forest University

title

Dynamics of Charge Carrier Traps in Organic Semiconductors

type

Dissertation