MRS Bulletin

Technical Feature

Technical Feature

The Evolution of Organometallic Complexes in Organic Light-Emitting Devices

Mark Thompson


This article is an edited transcript of the MRS Medal presentation given by Mark Thompson (University of Southern California) on November 28, 2006, at the Materials Research Society Fall Meeting in Boston. Thompson was awarded the Medal for the “development of highly efficient heavy-metal phosphor complexes.” The MRS Medal recognizes a specific outstanding recent discovery or advancement which is expected to have a major impact on the progress of any materials-related field.

Successful research efforts have led to improvements in the internal efficiencies of organic light-emitting devices (OLEDs) from 25% to 100%. The electroluminescence process in OLEDs involves the formation of both singlet and triplet excitons, formed in a ratio of 1:3. There is a drive to improve spin statistics by developing compounds in which triplet excitons, in addition to singlet excitons, can be used efficiently. Success with the incorporation of heavy-metal–based phosphors into OLEDs, in which the strong spin-orbit coupling of the metal atom allows for efficient molecular phosphorescence from triplet excitons, resulted in the identification and synthesis of an iridium complex, fac-tris-phenylpyridine iridium, with internal efficiencies of 100%. This, in turn, has led to the synthesis of more than 100 iridium- and platinum-based compounds, which have become the most efficient light-emitting compounds yet discovered. Intellectual property from Thompson's research in this field has led to more than 50 U.S. patents and substantial entrepreneurial investment toward commercial applications and devices.

Mark Thompson is professor of chemistry and chair of the Chemistry Depart ment at the University of Southern California. He received his BS degree in chemistry from the University of California, Berkeley, in 1980 and his PhD degree in chemistry from the California Institute of Technology in 1985. Thompson spent two years as an SERC fellow in the Inorganic Chemistry Laboratory at Oxford University. He then took a position as an assistant professor in the Chemistry Department at Princeton University in 1987. In 1995, Thompson moved his research team to USC. His research program involves the study of new materials and devices for electroluminescence, solar energy conversion, chemical/biological sensing, and catalysis.

Thompson can be reached at USC Chemistry Department, 810 Downey Way, Laird J. Stabler Laboratories, Rm. 268, Los Angeles, CA 90089-0744, USA; tel. 213-740-6402, fax 213-740-8594, and e-mail