Colloidal quantum dots are extremely small semiconductor particles which are as small as a few nanometers in size. With their small size, CQDs offer unique optical and electronic properties including absorbing and emitting light. Moreover, their properties change with their size and shape; smaller quantum dots emit in the blue range while larger quantum dots emit in the red.
(Image: Samsung)
The use of colloidal quantum dot in LEDs has become one of the key ingredients as the implementation of these nanocrystals in devices for optical sensing in the short-wave and mid- infrared can enhance applications including surveillance, night vision, and environmental monitoring.
A research team from ICFO-Institut de Ciencies FotoniquesIn at the Barcelona Institute of Science and Technology developed colloidal quantum dots infrared emitting LEDs, which have achieved an external quantum efficiency of 7.9% and an unprecedented power conversion efficiency of 9.3%.The result was published in Nature Nanotechnology on December 3rd, 2018.
The research achievements prove that the engineering of QCD infrared-emitting LEDs at the nanoscale integrated in solar cells can significantly improve the performance efficiency of these devices in the infrared range. The results provide opportunities for a wider range of application such as on-chip spectrometers for food inspection, environmental monitoring, as well as active imaging systems for biomedical or night vision applications.