Nanowire approach could bring faster, more robust electronic devices

The team has recently demonstrated 3D nanowire transistors created using this approach and believes these will open 'exciting opportunities' for the integration of materials such as gallium nitride on silicon substrates. The researchers have also been able to make these nanowires operate as transistors and to combine them into more complex circuits, as well as creating devices that are responsive to light. Conventional silicon devices have reached their lower size limit, said Professor Saif Ismal, restricting operation speed and integration density. Additionally, conventional silicon circuits cannot function at temperatures of more than 250°, nor handle high power, high voltage or optical applications. "Silicon can't do everything," he said. He anticipates the technology being used for applications such as sensors that can operate under high temperatures, for example inside aircraft engines. "In the foreseeable future, society will be dependent on a variety of sensors and control systems that operate in extreme environments," Prof Islam continued. He believes devices that include silicon and nonsilicon materials will offer higher speeds and more robust performance. To achieve this, Prof Islam's laboratory has created silicon wafers with 'nanopillars' of materials such as gallium arsenide, gallium nitride or indium phosphide, with nanowire 'bridges' between them. "We can't grow films of these other materials on silicon, but we can grow them as nanowires," he noted.