0 20 40 60 8010-6

10-5

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100

0

1

As fabricated in air After 1 year in air After 2 years in air After 4 years in air

I ds (

A)

Vgs (V)

I ds1/

2 (A

1/2 )

We have studied the stability and durability of n-channel polymer thin film transistors in air and under extreme conditions. High-mobility n-channel polymer transistors based on the polymer BBL were developed in our group under a previous NSF support. In a continuing study with current NSF support, we have found that the BBL transistors exhibit excellent stability and durability over a period of 4 years. The n-channel BBL transistors also showed robustness under extreme conditions such as direct exposure to high-energy plasma. The highly crystalline and efficient π-stacking nature of BBL explain its rugged electron-transport properties. Our findings provide guidelines for designing new polymer semiconductors with enhanced robustness and durability.

Highly Stable and Durable n-Channel Polymer TransistorsSamson A. Jenekhe, University of Washington, DMR 0805259

0 20 40 60 8010-5

10-4

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100

101

0

1

2

3

As Fabricated After Plasma Treatment

I ds (

A)

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(V)

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2 (A

1/2 )

GateDielectric

OO22 OO22OO22 HH22OOHH22OOOO22

HH22OO

ee–– ee–– ee–– ee––ee––

nN

N N

O O

N

BBL

Graduate Education in Science & Engineering: An important component of this research project

is the education of graduate students in the areas of chemistry, chemical engineering, and materials science and engineering. During this reporting period 3 female graduate students, partially supported by this grant, completed their PhD degrees: Pei-Tzu Wu, PhD in chemical engineering; Tricia Youngbull, PhD in materials science and engineering; and Eilaf Ahmed, PhD in Chemistry.

Outreach: The UW STEM Bridge Program at the University

of Washington is designed to motivate incoming first year minority students preparing to study Science, Technology, Engineering, and Mathematics disciplines.

During the design lab session, the students learn about the engineering profession and are introduced to an engineering system and design. The students are also engaged in the academic community that will become a vital part of their successful engineering careers.

Graduate student Taeshik Earmme (Bottom, right) is fabricating PhOLEDs in design lab with incoming pre-engineering students.

Graduate students who completed their PhD degrees: Tricia Youngbull, MSE (Left picture), Eilaf Ahmed, Chemistry (Right picture, left) and Pei-Tzu Wu, ChemE (Right picture, right).

Highly Stable and Durable n-Channel Polymer TransistorsSamson A. Jenekhe, University of Washington, DMR 0805259