Researchers create 2D electron gas, claim semiconductor alternative

In a move to find alternatives to current semiconducting materials, researchers at the Vienna University of Technology have created a two dimensional electron gas in strontium titanate. The electron gas exists in a thin layer just below the surface where electrons can move freely and occupy different quantum states.

The electron gas in the material is said to exhibit a multitude of different electronic structures and researchers say some of them could be suitable for producing interesting magnetic effects or superconductivity; properties that are not exhibited by the materials used in current electronic devices. The work is based on the principle that while every titanium atom has six neighbouring oxygen atoms, those at the surface are only connected to four oxygen atoms. When the material is irradiated with high energy electromagnetic waves, oxygen atoms can be removed from the surface. Other oxygen atoms then move up to the surface, creating an 'oxygen deficiency' and a surplus of electrons. Depending on the intensity of the radiation, the number of electrons varies and, by adding different atoms, the electronic properties can also be changed.