Researchers from Hong Kong University and Korea Electrotech Research Institute used 3D printing to create nanoscale display perovskite pixels. The 3D printed light-emitting perovskites have applications in security that were previously impossible.
In the past, liquid inks and direct ink writing were used to fabricate light-emitting display pixels. This team of researchers turned their attention to perovskite to demonstrate that the new deposition-based 3D printing technique could achieve create perovskite-based pixels with better brightness and higher resolution displays.
Perovskites are a promising material for optoelectronic applications thanks to their structure and tunability. The material offers large optical absorption, long carrier diffusion length, high carrier mobility and can emit light in the presence of an electrical voltage. In the past, perovskites have been limited to 2D systems due to the lack of 3D production methods.
The most recent study proves that pixel light intensity can be saturated further by increasing the optical system's depth of field to measure pixels. Better saturation can be used to enable more advanced applications with 3D printed perovskites.
Information can be stored securely at different heights in the new perovskite pixel. This data would only be accessible using a specific 3D measuring method that only the developers of the pixels would have access to.
There are many applications for the new pixels, including in high-resolution displays to filter color in backlit display devices. The pixels could also be used in authentication, identification and currency counterfeiting. Another application would be in multilevel encryption with fluorescent patterns that are only visible using ultraviolet light microscopes and a specialized 3D measurement system. This security tech would allow central banks to verify if a specific banknote is authentic or not by checking the fluorescent patterning.
The team is now focusing on transitioning from passive illumination to electrically driven lighting with the 3D printed perovskite pixels.
A paper on this research was published in NanoLetters.