Three-dimensional sensing of surfaces by projection of invisible electroluminescence from organic light-emitting diodes.

Yamada, Nishiki; Nakanotani, Hajime; Takagi, Akitsuna; Mamada, Masashi; Balijapalli, Umamahesh; Ichikawa, Tatsuya; Hirata, Eiji; Kaizu, Shun et al. · Sci Adv · 2024

basic_science · Level V

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Abstract

Organic light-emitting diodes (OLEDs) that efficiently emit near-infrared (NIR) light and consume little power will create valuable applications for OLEDs beyond just displays. Here, we report such a NIR-OLED with high operational stability that can be used as a light source for three-dimensional sensing of object's surfaces. Using a narrow-energy-gap material as a host for producing NIR hyperfluorescence system, we fabricated a NIR-OLED exhibiting intense emission at 930 nm with a high external electroluminescence quantum efficiency of more than 1% at a current density of 100 milliamperes per square meter without any degradation even after more than 300 hours of operation. The NIR-OLEDs were integrated with dense complementary metal-oxide semiconductor circuits to make a micro-NIR-OLED projector (0.21 inch, 230,400 pixels). By actively driving the projector on a pixel by pixel and projecting their emission onto objects, we successfully scanned and sensed the surfaces in three dimensions with invisible NIR.