The National Institute of Standards and Technology (NIST) in Gaithersburg, Md., has issued its first standard for the chemical composition of thin-film semiconductor alloys, with the goal of improving a wide range of optical electronic devices. Standard Reference Material (SRM) 2841, a small piece of semiconductor about the size of a button, coated with aluminum, gallium and arsenic (AlGaAs), was requested by the compound semiconductor industry to help measure and control thin film composition as a basis for optimizing material and device properties. The SRM can be used by companies that grow or characterize thin films or use them to make devices, as well as government and university laboratories, to calibrate equipment for making or analyzing these materials. AlGaAs is used as a barrier material to increase conductivity in high-speed circuits for wireless communication; semiconductor lasers for optical disk drives, bar code scanning, xerography and laser surgery; and LEDs for remote controls, traffic lights and medical instruments. NIST said the standard is expected to increase the accuracy of chemical characterization of AlGaAs films by an order of magnitude over the current standard, which will help reduce waste, increase the free exchange of thin film materials between vendors and customers and improve the accuracy of data on relationships between material composition and properties. SRM 2841 can be ordered at: http://ts.nist.gov/ts/htdocs/230/232/232.htm