SoylentNews

upstart writes in with an IRC submission for RandomFactor:

Transparent near-infrared light-emitting diodes:

Near-infrared (NIR) covert illumination is increasingly important for facial recognition, motion sensing and depth sensing functions in mobile devices. However, these NIR illumination sources, which are usually non–transparent LED chips, occupy valuable space and could lead to unsightly black notches on an otherwise full-area color display.

[...] Their devices employ an ultra-thin layer of a novel perovskite-based semiconductor, which is capable of intense and efficient light emission. This perovskite semiconductor also benefits from low-cost processing and versatile integration into a variety of device substrates. By further replacing the traditional non-transparent metallic electrode with a new electrode comprising layers of ultra-thin metals and conductive oxide, the team is able to achieve an optimal balance of high optical transparency, low electrode resistance, and efficient charge injection that are required for the LED to generate light efficiently.

Mr Xie Chenchao, a Ph.D. student on the research team said, "We found that the implementation of a thin aluminum interlayer in our transparent electrode greatly reduced plasma damage to our device during the electrode deposition process, and allowed our devices to function efficiently."

Journal Reference:
Chenchao Xie, Xiaofei Zhao, Evon Woan Yuann Ong, et al. Transparent near-infrared perovskite light-emitting diodes [open], Nature Communications (DOI: 10.1038/s41467-020-18110-7)

Original Submission