A bright-light-emitting tool is been developed by the UC Berkeley engineers that are millimeters wide and completely translucent when switched off. The tool unlocks the way to invisible displays on windows and walls—displays that will be bright when switched on but transparent when switched off—as per the scientists.
The tool was built in Ali Javey’s laboratory, who is an Electrical Engineering and Computer Sciences Professor at Berkeley. Javey’s laboratory, in 2015, published a study demonstrating that monolayer semiconductors are able to emit bright light, but closed short of developing a light-emitting tool. The new study surpassed the fundamental obstacles in using LED technology on the monolayer semiconductors, enabling for such tools to be ranged from sizes lesser than the human hair’s thickness up to several millimeters.
Commercial LEDs contain a semiconductor substance that is electrically inserted with negative and positive charges that generate light when they come in contact. Usually, 2 contact points are utilized in a semiconductor-supported light-emitting tool; one for adding positively charged particles and other for adding negatively charged particles. A fundamental obstacle for LEDs is making contacts that could competently add these charges and it is mainly tricky for monolayer semiconductors as there is so slight substance to function with.
A method was engineered by the Berkeley research team to dodge this obstacle by developing a new tool that needs one contact only on the semiconductor. By placing on an insulator the semiconductor monolayer and situating the electrodes on monolayer and beneath the insulator, the team can exert an AC signal through the insulator. When the polarity is switched by the AC signal to negative from positive (and vice versa), during this moment, both negative and positive charges exist simultaneously in the semiconductor, producing light.
The team demonstrated that this device functions in 4 diverse monolayer substances, all of which give out diverse light colors. This tool is a proof-of-concept and more study still remains, mainly to enhance efficiency.