It is reported that a low-cost, recyclable and easy to manufacture lighting technology can be manufactured with light-emitting electrochemical cells (LEC). The battery is a thin-film electronic and ionic device that produces light when a low voltage is applied. Recently, researchers at the Technical University of Munich (tum) in Germany and the University of Turin in Italy have now used extensive data analysis to produce first-class LEC from copper complexes emitting blue and white light.
This LEC is by far the simplest and cheapest thin-film lighting device, which consists of a single active layer. They can be used as electroluminescent inks and stickers.
The electroluminescence effect was first confirmed in 1905. At that time, the two scientists detected the presence of light under applied voltage in various minerals and metals and were able to correlate the intensity with voltage and heat generation. Their prototype is considered to be the first LED.
"However, the technical application of this effect was not possible until later. The well-known light-emitting diode or LED is a semiconductor device that emits light when voltage is applied, and the light-emitting electrochemical cells or LECs we are studying follow different principles." Ruben D. Costa, Professor of biological gene functional materials at Munich University of technology, explained.
It is reported that the research team led by Professor Ruben D. Costa of tum straubin biotechnology and sustainable development campus and Professor Claudia Barolo of the University of Turin has developed the first method to develop LEC transmitters in the so-called active layer. These LECs are based on copper (L) complexes and can produce excellent blue and white light.
"The development of cheap devices that can emit white and blue light is very needed and has many benefits. However, the lack of blue emitters in the past has hindered the transition from the laboratory to the actual market. Therefore, the creation of blue emitters is a common problem. The milestone of thin-film lighting. Once blue devices appear, we will be able to manufacture white light devices relatively easily."
The research team has now successfully developed a blue transmitter. They successfully used data science tools to establish the statistical relationship between the X-ray structure and the electronic characteristics of copper (L) complex diamine and diphosphine ligands. At the same time, they studied the structure and electronic parameters and their relationship to determine the emission color, efficiency and luminosity of the device.
After a large amount of data evaluation of various known methods, a new blue LEC design has emerged, which provides excellent performance compared with devices with traditional transmitters.
Professor Claudia Barolo of the University of Turin said, "with the new high-performance blue LEC, a copper (L) based single-layer white LEC with high-quality white light and 90 color rendering index can be realized." The color rendering index represents the natural color display of the illuminated object under a given light source. The maximum value is 100, so the value of 90 is good.
This work points out a new way to simplify the design of emitter and active layer in thin film illumination. "We believe that our analytical model is the first step towards advanced machine learning methods and the fine design of other active compounds," Professor Costa said