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CPM Seminar
Boron Nitride Polymers and Electronic Mobility in Organic Semiconductors Michel Côté Cambridge Organic materials are the subject of intense research motivated by promising applications for electronic devices. I will present recent calculations on two topics concerning this class of materials: the design of new polymers based on boron nitride and the electronic transport properties of molecular crystals. Modern optoelectronic devices are increasingly being designed by combining materials with different electronic properties. The conventional semiconductor industry has achieved this by building quantum wells from materials with the same crystal structure but different constituent atoms. We propose that boron nitride polymers will allow the same idea to be applied to polymer materials, providing new building blocks for organic devices. We assess the properties of these new polymers by means of density-functional theory calculations. The second topic deals with the mobility of organic semiconductors. One reason that currently limits the wide application of organic materials is the low mobilities of carriers in those compounds. However, recent experiments on pentacene single crystals show that the mobility of holes can reach values comparable to inorganic semiconductors. Using the information from ab initio calculations, we solve the full Boltzmann equation in order to determine the transport properties. These two topics also illustrate how density-functional theory calculations can be used to validate ideas, predict properties of new materials and to help interpret experiments by understanding the microscopic charateristics of the studied compounds.
Thursday, April 6th 2000, 15:30 |