Date of Award

Summer 8-6-2015

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)

Department

Chemistry and Biochemistry

Committee Chair

Dr. Song Guo

Committee Chair Department

Chemistry and Biochemistry

Committee Member 2

Dr. Janice Paige

Committee Member 2 Department

Chemistry and Biochemistry

Committee Member 3

Dr. Wujian Miao

Committee Member 3 Department

Chemistry and Biochemistry

Abstract

Organic thin films can be readily mass-produced through solution-based fabrication methods including ink-printing and solution-casting because their light weight, flexibility, and inexpensive sources. Their applications range from organic field-effect transistors (OFET), organic solar cells (OSC), to organic light emitting diodes (OLEDs). Compared with pure component films, binary organic thin films (BOTF) allows for novel characteristics and specialized features to handle more demanding tasks. Due to the complex intermolecular interactions in BOTF, various microscopic phases with different morphological and electronic properties may be formed and this information is difficult to extract through conventional bulk measurements.

Organic thin films can be readily mass-produced through solution-based fabrication methods , including ink-printing and solution-casting because their light weight, flexibility, and inexpensive sources. Their applications range from organic field-effect transistors (OFET), organic solar cells (OSC), to organic light emitting diodes (OLEDs). Compared with pure component films, binary organic thin films (BOTF) allow for novel characteristics and specialized features to handle more demanding tasks. Due to the complex intermolecular interactions in BOTF, various microscopic phases with different morphological and electronic properties may be formed , and this information is difficult to extract through conventional bulk measurements. This study focused on investigating the binary mixture of DH6T and PCBM thin films on HOPG through Atomic Force Microscopy (AFM) and Kelvin Probe Force Microscope (KPFM). Films of pure DH6T and pure PCBM and their mixture films were systematically analyzed to reveal topography and surface potential of different phases. This study found a vertical packing system of pure DH6T on HOPG surface in island forms. PCBM had a full coverage on the substrate with occasional pits which had been seen in previous studies. When adding different concentrations of PCBM to DH6T, the islands had changes in height as well as the presence of new morphology features that possibly consist of mostly PCBM. With this study , further analysis via annealings as well as energy minimization simulations may deepen our understanding about molecular interactions of the DH6T/PCBM mixture at a microscopic scale.