Researchers at the University of Toronto have created a semiconductor device that outperforms today’s conventional chips — and they made it simply by painting a liquid onto a piece of glass. Conventional semiconductors have produced spectacular results, but they rely on growing atomically-perfect crystals at 1,000 degrees Celsius and above, he explains.
The Toronto team instead cooked up semiconductor particles in a flask containing extra-pure oleic acid, the main ingredient in olive oil. The particles are just a few nanometres (one billionth of a metre) across. The team then placed a drop of solution on a glass slide patterned with gold electrodes and forced the drop to spread out into a smooth, continuous semiconductor film using a process called spin-coating. They then gave their film a two-hour bath in methanol. Once the solvent evaporated, it left an 800 nanometre-thick layer of the light-sensitive nanoparticles. At room temperature, the paint-on photodetectors were about ten times more sensitive to infrared rays than the sensors that are currently used in military night-vision and biomedical imaging.
Source: University of Toronto