13 Apr 2020
Team at Linköping University with partners in China say development is significant for miniaturization of OE components.Linköping University, Sweden, (LiU) together with colleagues in China, have developed a tiny photonic device that is simultaneously both an optical transmitter and a receiver. “This is highly significant for the miniaturisation of optoelectronic systems,” commented LiU professor Feng Gao.
In a demonstration of the new device’s capabilities, Chunxiong Bao, a postdoc researcher at Linköping, typed in a sentence on a computer screen, and the same sentence immediately appeared on a neighbouring screen. The message had been optically transferred from one diode to another. The diode is made from a form of perovskite. The latest work is described in an article in Nature Electronics.
Besides their well-documented photovoltaic applications, perovskites also have the useful property of both detecting and emitting light. The Linköping University team, together with colleagues in China, have developed a diode that can be directed in two directions: it can receive optical signals and just as easily transmit them.
This capability means that data can be wirelessly transmitted from one unit to the other and back again, using two identical units – “effectively in real time,” commented LiU scientists Chunxiong Bao and Feng Gao.
In the autumn of 2018, Chunxiong Bao discovered the correct perovskite from which to build a photodetector showing higher performance and longer lifetime.
The development of light-emitting diodes made from perovskites has also made rapid progress. Weidong Xu, postdoc at Linköping, developed a perovskite LED with an efficiency of 21% in 2019, and published the results in Nature Photonics. What the scientists have now achieved is the development of a perovskite that comprises a light-emitting diode and is simultaneously an excellent photodetector.
Current optical communication systems use photodetectors made from materials such as silicon and indium gallium arsenide. These are, however, relatively expensive and they cannot be used in applications that require low weight, flexibility, or large surfaces.
“In order to demonstrate the potential of our diode with double function, we have built a monolithic sensor that detects heart beats in real time, and an optical, bidirectional communication system,” said Chunxiong Bao, researcher in the university’s Department of Biomolecular and Organic Electronics.
This tiny unit that can both receive and transmit optical signals provides an opportunity to simplify and shrink the functionality of the current optical systems, in particular given that it can also be integrated with traditional electronic circuits.
“We have managed to integrate optical signal transmission and reception into one circuit, something that makes it possible to transmit optical signals in both directions between two identical circuits.
"This is valuable in the field of miniaturized and integrated optoelectronics”, commented Feng Gao, professor and head of research at the Department of Biomolecular and Organic Electronics.