ARGONNE, Ill. (Dec. 19, 2007) The fan in your computer is there to keep the microprocessor chip from heating to the point where its component materials start to expand, inducing cracks that interrupt the flow of electricity and not incidentally, ruin the chip. Thermal expansion can also separate semiconducting materials from the substrate, reduce performance through changes in the electronic structure of the material or warp the delicate structures that emit laser light.
Recently published research by scientists at the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) and Argonne National Laboratory and academic institutions has shed light on a semiconducting material with zero thermal expansion (ZTE). The research may play a role in the design of future generations of electronics and optoelectronics that can withstand a wide range of temperatures.
Traditional interests in ZTE materials have largely been in areas such as optics, heat-engine components and kitchenware. ZTE materials with applications in non-conventional areas such as electronics and optoelectronics are rare; most are glasses, which do not work well in electronics applications. The hybrid inorganic-organic semiconductor investigated in this work is a multifunctional semiconductor that has previously been shown to possess superior electronic and optical properties. The work also suggests an alternative route to designing materials with any desired positive or negative thermal expansion.
Its a merger of inorganic and organic materials, said Zahirul Islam, a physicist in Argonnes X-Ray Science Division, which form a fully coherent, three-dimensionally ordered crystal. Normally inorganic and organic materials don't work very well together, but here they are working together to display these remarkable properties.
The materials under study form alternating organic and inorganic layers that work together to produce these effects. One co
|Contact: Steve McGregor|
DOE/Argonne National Laboratory