From Materials Design to Technology Development: High-Performance Organic Electronic and Photonic Materials

Featuring Henry Yan, Ph.D.

Polyera Corporation

Hosted by:  UCI Environment Institute: Global Change, Energy, and Sustainable Resources and the Department of Chemical Engineering and Materials Science

Organic Electronics has emerged as a very important research field in the past two decades. Organic electronic materials have enabled several exciting new technologies including Organic Light-Emitting Diodes (OLED), Organic Field-Effect Transistors (OFET), and Organic Photovoltaics (OPV). While these new technologies offer unique features such as light-weight, mechanical flexibility, and easy printability, they could also help us address some of the important energy and environmental issues we are facing. For example, OPV offers an ultra-high-throughput solar cell technology that can produce plastic solar cells like the printing of newspapers. With OFET, low-cost flexible e-readers become possible, which could replace books and newspapers to reduce paper productions and paper wastes. In this presentation, the speaker will first discuss the design of organic materials for OFET and OPV applications and talk about the relationship between molecular structures and electrical characteristics of organic electronics. The speaker will also introduce some new materials developed at Polyera and explain how these materials will impact technology developments in the OFET and OPV areas.

More specifically, for the OFET area, it is highly desirable to have both p- and n-type organic

semiconductors to construct complimentary circuits (CMOS circuits). However, the development of n-type organic semiconductors had been extremely slow and seriously limiting the development of the OFET field. This presentation will introduce the first high-mobility (up to 0.8cm2/Vs) n-type polymeric semiconductor in the OFET community. With this material, printed CMOS invertors were demonstrated with unprecedented performance. This development opened up tremendous opportunities of applications of organic materials in the Printed Electronics industry.

In the OPV area, there have been rapid progresses of power conversion efficiencies in the past two years from 4% to about 8%. An important approach to enhance OPV efficiency is to develop low band-gap polymers that have wide absorptions in the solar spectrum. This presentation will briefly introduce the general design rationales of low-band-gap polymers, and discuss about the polymer materials developed at Polyera giving >7% power conversion efficiency.

References:

1. Nature, (2009), 457, 679-687

2. Advanced Materials, (2008), 20, 3393-3398