Method to Increase Electrical Conductivity of a Crystal
Thursday, November 14, 2013
Scientists from Washington State University have achieved a whooping 400 fold increase in electrical conductivity of a crystal after it was accidentally exposed to light. The readings are attributed to photoconductivity which increases electrical conductivity in a material due to absorption of electromagnetic radiation such as visible light, ultraviolet light, infrared light or gamma radiation.
Scientists Marianne Tarun and Mathew McCluskey came across this discovery when they noticed that the conductivity of strontium titanate had shot up after it was left out one day. The effect was thought to be due to contamination initially, but later experiments showed that it was due to exposure to light. The phenomenon witnessed, is known as ‘persistent photoconductivity’.
Though persistent photoconductivity is nowhere close to superconductivity, the discovery can make devices work which presently require superconductors. What’s more interesting is that it worked at room temperature whereas superconductors need refrigeration. Scientists who had earlier tried to achieve superconductivity have done so at sub-zero temperatures. Tarun and McCluskey feel that if the crystal strontium titanate made up of oxygen and two other elements can survive room temperatures, it could store information throughout its volume. The approach known as holographic memory could lead to revolutionary increase in the storage capacity of computer memory.