Crystallization of TES ADT in Constrained Channels Abby
Grosskopf, Anna Hailey, Lynn Loo Loo Lab Group: Polymer and Organic
Electronics Laboratory Princeton University
Slide 2
Background Information Organic Semiconductor: An organic
material with an electrical conductivity Benefits of using organic
semiconductors over inorganic semiconductors: -Solution-processable
-Inexpensive to fabricate -Suitable for large area processing Thin
films comprising organic molecules have promising applications,
such as organic thin film transistors, and solar cells.
http://www.sigmaaldrich.com/technical-documents/articles/material-
matters/organic-materials.html
http://www.sunnysolarlightgarden.com/solar-yard-lights-work/
Slide 3
Crystallization of TES ADT TES ADT is a solution-processable
organic semiconductor. TES ADT undergoes spherulitic growth when
spin coated from 2 wt% solution in toluene then exposed to
1,2-dichloroethane vapor. as-spun film crystallized film Expose to
1,2-dichloroethane vapor 1 Spin-coat from 2 wt% solution in toluene
250 m Lee, Stephanie. (2012). Processing-Structure- Function
Relationships In Solution-Processed, Organic-Semiconductor Thin
Films for Transistor Applications. Ph.D. Thesis. Princeton
University.: US. Graphics thanks to Anna Hailey
Slide 4
TES ADT and Guiding Crystallization Utilizing differences in
TES ADT growth rate on SIO2 vs PFBT-treated Au, growth can be
specified along channels. Guiding crystallization allows us to
pattern TES ADT into predefined pathways which can potentially have
applications in organic electronics. Lee, Stephanie. (2012).
Processing-Structure- Function Relationships In Solution-Processed,
Organic-Semiconductor Thin Films for Transistor Applications. Ph.D.
Thesis. Princeton University: US.
Slide 5
My Project What are the limits to guiding growth of TES ADT on
patterned substrates? What is the smallest feature size that we can
pattern with TES ADT? By understanding more about the growth of TES
ADT in channels, we hope to pattern electronics in more elaborate
and efficient ways to create new devices and save energy.
Slide 6
Haatajas Group Predictions V denotes the growth rate, M denotes
mobility, denotes interfacial forces, E denotes the bulk driving
force of crystallization, denotes interfacial curvature, and w
denotes channel width. Sri Muralidharans PhD Thesis: Muralidharan,
Srevatsan. (2012). Continuum Studies of Microstructure Formation in
Metallic and Organic Thin Films. Ph.D. Thesis. Princeton
University: U.S.
Slide 7
TES ADT Growth in Channels 1000um
Slide 8
TES ADT Growth into Corners 1000um
Slide 9
Alta Fangs Predictions No TES ADT Leaking Out of Corner:TES ADT
Leaking Out of Corner: The crystal growth outside of the pattern
will always drag the crystal growth front up and over the corner.
Instantaneous Velocity vs. 1/(width of pattern at growth
front)
Slide 10
Results: Different Corners Critical Widths: 1.7 um, 2.0 um, 2.5
um
Slide 11
Results: Channel and Corner Data Combined Using the predicted
equation, the averaged critical channel width is 2 um.
Slide 12
Closing Remarks - Learned new lab techniques, data analysis
skills, and the fundamentals of day-to-day laboratory research -
Gained a new perspective on the vast amount of applications of
chemical engineering in scientific research - Looking forward to
using what I learned this summer in future independent work!