Transistors made with oxide-based semiconductors may soon replace the silicon-versions commonly used in LCD screens.
A team from the University of Manchester has created an ultrafast, nanoscale transistor called a thin film transistor (TFT) made out of an oxide semiconductor, which could enable flexible televisions, tablets and phones, as well as wearable smart technology.
“Wearable electronics requires flexibility and in many cases transparency, too,” Aimin Song, a professor of Nanoelectronics in the School of Electrical & Electronic Engineering, said in a statement. “This would be the perfect application for our research. Plus, there is a trend in developing smart homes, smart hospitals and smart cities – in all of which oxide semiconductor TFTs will play a key role.”
The new transistor represents the first oxide-semiconductor based transistor capable of operating at one GHz, making the next generation of personal electronics faster, brighter and more flexible than before.
“TVs can already be made extremely thin and bright,” Song said. “Our work may help make TV more mechanically flexible and even cheaper to produce. But, perhaps even more importantly, our GHz transistors may enable medium or even high performance flexible electronic circuits, such as truly wearable electronics.”
Thin film transistors are primarily used in the LCDs commonly found in smart phones, tablets and high-definition televisions. In an LCD, a TFT behind each individual pixel acts as an individual switch to allow the pixels to rapidly change their states, making them turn on and off quicker.
Most current TFTs are silicon-based, which are opaque and more rigid and expensive than the oxide semiconductor family of transistors.
However, more still needs to be done before the new transistors can be implemented into new technology.
“To commercialize oxide-based electronics there is still a range of research and development that has to be carried out on materials, lithography, device design, testing, and last but not the least, large-area manufacturing,” Song said. “It took many decades for silicon technology to get this far, and oxides are progressing at a much faster pace.
“Making a high performance device, like our GHz IGZO transistor, is challenging because not only do materials need to be optimized, a range of issues regarding device design, fabrication and tests also have to be investigated,” he added. “In 2015, we were able to demonstrate the fastest flexible diodes using oxide semiconductors, reaching 6.3 GHz, and it is still the world record to date. So we’re confident in oxide-semiconductor based technologies.”
The study was published in IEEE Transactions on Electron Devices.