Innovative Materials for High - Performance Optoelectronic Devices

Aldrich brand products are sold through Sigma-Aldrich Co. LLC. Purchaser must determine the suitability of the product for its particular use. See product information on the Sigma-Aldrich website at sigma-aldrich.com and/or on the reverse side of invoice or packing slip for additional terms and conditions of sale. All prices are subject to change without notice. Introduction Welcome to the first issue of Material Matters™ for 2012, focused on high-performance organic optoelectronic devices. Since their discovery, devices such as organic light-emitting diodes (OLEDs), organic photovoltaic solar cells (OPVs), and organic field effect transistors (OFETs) have triggered enormous scientific interest, as well as skepticism regarding their potential for commercial application. As of today, there are several notable examples that have made their high-performance future much brighter: organic solar cells based on conjugated polymers and fullerene derivatives blends have achieved nearly a 10-fold improvement of power conversion efficiency as compared to a decade ago; optimized OLEDs are approaching their theoretical limit in internal quantum efficiency; OFETs comprised of conjugated polymers have demonstrated carrier mobilities competitive with amorphous silicon. Moreover, OLEDs are now integrated in commercial display and lighting products. Researchers continue to make significant advances in materials chemistry and device engineering of organic semiconductors that will further the potential for commercial success of OLED, OFET, and OPV devices. In this issue, we discuss a variety of innovative materials, including both organic/polymeric molecules and inorganic nanomaterials, which have made superior optoelectronic devices become reality. In the first article, Asanga B. Padmaperuma and Evgueni Polikarpov (Applied Materials Group, Pacific Northwest National Laboratory) describe a process to design functional OLED materials by correlating theoretical predictions and experimental measurements. This approach enables researchers to identify novel host and charge carrier materials with predicted electronic properties for optimized OLED performance. In the next article, Professor Thuc-Quyen Nguyen (University of California, Santa Barbara) illustrates her group's recent developments in conjugated small molecules containing a series of diketopyrrolopyrrole (DPP)-based chromophores for the fabrication of optoelectronic devices. They demonstrate the benefit of small molecules over their polymeric counterparts in terms of precise control over material properties. In the following article, Professor Alejandro L. Briseño and his group at the University of Massachusetts, Amherst summarize the synthetic history of thiophene-based materials for organic electronics and emphasize the importance of new processing techniques to increase crystallinity, which further improves device performance. Finally, Benny Pacheco and Scott Kordyban (Cytodiagnostics, Inc.) highlight some of the …