Transparent circuitry to power smart windows
Scientists at King Abdullah University of Science & Technology (KAUST), Saudi Arabai, have found a way to make transparent transistors and other essential components of electronic circuitry, an advance that may lead to displays on car windscreens, transparent television sets and smartwindows.
Indium tin oxide (ITO) is the current material of choice for electronics because it combines optical transparency with electrical conductivity. Its use ranges from touch-sensitive smartphone screens to light-harvesting solar panels. Indium is in short supply, and as demand increases for ITO-containing devices, so does the price of indium.
A low-cost ITO alternative is a transparent material known as aluminium-doped zinc oxide (AZO).
Researchers have used a high-precision technology called atomic layer deposition, a process in which the circuitry is built with a single layer of atoms at a time. Volatile vapours of aluminium and zinc in the form of trimethyl-aluminium and diethyl-zinc are alternately introduced onto the transparent substrate, where these adhere to the surface in
a single layer before reacting in situ to form AZO.