UC Berkeley

Organic electronics is an emerging technology with advantages of mechanical flexibility,

solution-processability, and high-throughput manufacturing at low temperatures on inexpensive

and light-weight substrates such as plastic, paper, and fiber in large-scales not possible

with high-temperature processing techniques. While the performance of devices cannot rival

the silicon counterpart, the performance should be tuned to meet the required specifications

of the application in mind. This thesis will overview the performance of the organic thin

transistors (OTFTs) and organic phototransistors (OPTs) optimized and used for circuits

and large area sensing applications. The work first covers the printing techniques employed

for the fabrication of organic devices on the flexible substrate. There have been device-level

optimizations for scale ratio tuning and power improvement by using a bilayer gate dielectric

structure. We also introduce a novel technique for rapid and digital modulation of the scale

ratios. Interconnection is done with the screen printing method for the fabrication of printed

flexible logic circuits and an OTFT weak classifier for data classification. The OPTs, with

a good dual performance as both transistor and photodetector, are capable of merging the

sensing and function generation in one substrate, which can reduce system complexity.