Researchers found that light can quickly switch material between semiconducting and metallic states.
Many modern technologies are based on transistors, usually consisting of several semiconductors, which are inferior to metals in conductivity. This design limits their performance and the minimum size of the devices. Although their properties can be changed by chemical alloying, this process is irreversible..
Now a group of scientists from the Max Planck Society has discovered that by laser acting on the surface of semiconductor zinc oxide, it can be easily converted to metal and vice versa. This photo-doping is achieved due to the fact that light changes the electronic properties of the material. As a result, the electrons suddenly begin to move freely, and the current can flow as freely as in a metal. After turning off the light, zinc oxide quickly returns to semiconductor state.
SCL CHM 4102 (GROUP 4) : PHOTOELECTROCHEMISTRY
According to the researchers, despite completely different approaches, the optical method affects the material in the same way as chemical doping. They also note that huge changes can be made quickly in this way, even at very low laser powers. Switching occurs in just 20 femtoseconds.
This discovery could lead to the development of ultrafast optically controlled transistors. In the future, the group will study other semiconductors, hoping to find more energy efficient options..
Earlier, we also reported on the development of a technology that allows the production of metals 4 times harder the usual.
text: Ilya Bauer, photo and video: Max Planck Society