Phase Transition Switches Based on the Electrically induced Metal-Semiconductor Transition in VO(2)
Vanadium Oxide (VO(2)), which exhibits Metal Insulator transition (MIT), is a suitable material for making novel ultra low power switches. The MIT can be triggered by thermal or electrical stimulus. In case of thermal triggering, at a critical temperature of 340K, the VO(2) samples undergo a metal insulator transition where the resistance changes by 2 to 5 orders of magnitude depending on if the VO(2) sample is thin film or bulk. The thermal transition is accompanied by phase transition from monoclinic to tetragonal. In the
interest of making low power high speed switches, the triggering needs to be electronic. VO(2) undergoes a sharp metal-insulator transition (MIT) above room temperature at ultrafast timescales. This ultrafast resistance change opens up the possibility of making novel electronic switches, memory devices and sensors with VO(2). The MIT in VO(2) can be triggered by temperature induced structural phase transition known as Peierls or by electronic means known as Mott Hubbard transition.