Researchers at Linköping University in Sweden have developed a high efficiency perovskite LED and diode that can be used as an optical transmitter and a receiver.
The transceiver switches between modes by changing the bias direction. It exhibits light emission with an external quantum efficiency of over 21 per cent and a light detection of under a picowatt.
The operation speed for both functions can reach tens of megahertz and benefits from the small Stokes shift of perovskites to give the sensitivity at its peak emission of 804 nm. This allows an optical signal exchange between two identical diodes and was used to create a monolithic pulse sensor and a bidirectional optical communication system.
“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 Division of Biomolecular and Organic Electronics.
Bao has worked with Formamidinium lead bromide (FAPbBr3) nanocrystals (NCs) that demonstrate potential as a perovsite LED with a pure green emission and excellent stability.
Weidong Xu, postdoc at Linköping University, has also developed a perovskite LED with an efficiency of 21 per cent. The two worked on an LED that is also an excellent photodetector that can 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 miniaturised and integrated optoelectronics," said Feng Gao, professor and head of research at the Division of Biomolecular and Organic Electronics. "This is highly significant for the miniaturisation of optoelectronic systems."
The results were published in Nature Electronics.