Researchers developed tunable infrared light emitting diodes (LED) that can detect lethal gases and off food in your fridge.
Infrared spectrometers have been widely used in identification of materials based on the infrared print that materials emit. IR spectrometers can be tuned to different wavelengths, giving a broad-spectrum analysis of a gas sample. But these equipment are bulky and expensive and not usually practical to take out of the laboratory and into the field.
Researchers from University of Melbourne, the Lawrence Berkeley National Laboratory, the University of California, Berkeley, and the Australian Research Council Centre of Excellence for Transformative Meta-Optical Systems (TMOS) have developed a new infrared light emitting diode (LED) that is tunable to different wavelengths of light. It could tell you when your food is going off in the fridge, and identify certain materials from your phone.
“Our new technology bonds a thin layer of black phosphorus crystals to a flexible, plastic-like substrate, allowing it to be bent in ways that cause the black phosphorus to emit light of different wavelengths essentially creating a tunable infrared LED that allows for the detection of multiple materials,” University of Melbourne Professor Kenneth Crozier said. “This technology could fit inside smartphones and become part of everyday use.”
“The device placed inside a fridge could send a notification that meat is going off. When pointed at a handbag, it could reveal whether the bag is made of real leather or a cheaper substitute,” said Professor Crozier, who is also the Deputy Director of TMOS.
The black phosphorus technology only requires one layer allowing the device to be flexible, giving it unique properties when bent. Therefore manufacturing is easy.
“The shift in black phosphorus’ emission wavelength with bending is really quite dramatic, enabling the LED to be tuned across the mid-infrared,” said Professor Ali Javey, from the University of California at Berkeley, whose group led the work.
“Our IR photo detectors could be integrated into a camera so that we could look at our phone screen and ‘see’ gas leaks or emissions and be able to determine what kind of gas it is,” Professor Crozier said.
The research appeared in the journal Nature.