Engineers further development of transparent LED displays

Engineers at UC Berkeley and Lawrence Berkeley National Laboratory have developed a new process to create atom-thin materials which could advance the development of transparent LED displays. The process uses an organic super-acid to chemically treat a monolayer semiconductor made of molybdenum disulfide, or MoS2.

Monolayer semiconductors are of interest to manufacturers because of their low absorption of light. In addition the material can withstand twists and bends. These characteristics make monolayer semiconductors perfect for flexible display. A flexible display which is also transparent when powered off has a number of commercial applications such as digital signage and IPTV. 

With the process developed , researchers were able to increase the material's photo-luminescent efficiency, from one percent to a perfect 100 percent. The layers of MoS2 are only seven-tenths of a nanometre thick. Dipping the material in a superacid fixed defects by removing contaminants while also filling in missing atoms through a chemical reaction called protonation.

Ali Javey, principal investigator and a UC Berkeley professor, said: “This study presents the first demonstration of an optoelectronically perfect monolayer, which previously had been unheard of in a material this thin." 

In addition to transparent LED displays, Javey believes the process can also be used to remove defects in semi-conductors chips meant for computers as they become smaller and thinner. The team's work has been published in the journal Science.