High K Films: Organic Field Effect Transistors Using Self Assembled Barium Titanate Nanoparticles

Stephen P. O’Brien, Columbia University, DMR 0348938

In dielectric materials research, requirements for integrated electronics are generally towards miniaturization, higher permittivity (dielectric strength), lower loss/leakage. Highly crystalline and aggregate free barium titanate nanocrystals, viewed as “building blocks” for assembly, are strong candidates for ceramics processing in that chemical approaches provide potentially facile and cost efficient fabrication of films. A notable limitation, however, is the trade between the high temperature processing frequently required versus the unwanted loss of control over particle size and uniformity. Temperatures exceeding 400 °C are generally unfavorable with respect to many substrates and are a red light for any possibility of adoption by semiconductor industry integrated device manufacturers (IDMs).Self assembly of nanocrystals into thin films or offers a means to prepare high k materials with no annealing step, rendering them compatible with organic electronics fabrication. Shown here.

Films are prepared by chemical deposition of BaTiO3 nanocrystals on a variety fo substrates with no calcination step (SEM and TEM inset)

The ceramic film can be used as a high k gate dielectric in OFET devices prepared on flexible PEN substrates.

OFETs (Organic Field Effect Transistors), are alternatives to Si transistors

High K Films Using Self Assembled Barium Titanate Nanoparticles – Broader Impacts

Stephen P. O’Brien, Columbia University, DMR 0348938

Research and education in ceramic nanotechnology and materials chemistry, from undergraduate through post doctoral training: Our team of scientists is built from collaboration with groups across Materials, Chem E, EE, Chemistry and Physics. The enthusiasm of our students, post-docs and research scientists extends to outreach and education activities in the NYC area.

Zhuoying Chen and Kristi Hultman during High School Outreach visits to promote materials science. Zhang Jia and Dr. Limin Huang showing a poster at Nanoday in New York at City College New York.

Our research has evolved to have new consequences for Energy Storage applications in the form of novel high k capacitor technology. Energy storage is seen as part of the broader concern of the US to create a sustainable energy policy with proven consequences for generations to come, while serving an urgent need to define new solutions to our existing energy intensive economy. The importance of energy storage is reaching widespread recognition because all sources of alternative energy (e.g. wind, solar) are intermittent, and will only aid efficiency of electrical Grids if storage is also incorporated. New solutions are sought for optimizing Power density and Energy density (See figure)

A patented technology called Metacapacitors™: printed, self-assembled barium titanate nanoparticles are the basis for a capacitor architecture Collab: Ioannis Kymissis (Columbia University), Dan Steingart (City College NY), Alex Couzis (CCNY), Peter Kinget (CU)