Organic light-emitting diodes (OLEDs) is a new technology which has many advantages than the non-organic LED, as they are thinner, lighter, and less expensive to manufacture. Unfortunately they are not all organic as you might believe considering their name, because they get their glow using small amounts of precious metals.
But we might soon get the completely organic alternative and of course it is going to be even cheaper.
The researchers from the University of Michigan have created metal-free organic crystals that glow with phosphorescence, and that is new because up until now the phosphorescence was available in non-organic or semi-organic compounds only.
The crystals glow white when exposed to usual light, but it changes its colour to blue, green, yellow or orange when exposed to ultraviolet light. Changing their chemical composition will obtain them different colors.
The researches of Michigan University found that in the usual materials, the aromatic carbonyls which is molecules of oxygen and carbon, give a weak phosphorescence light only under the condition of very low temperatures as in Kim’s phosphors. So they tried to overcome that in their material. Using the aromatic carbonyls form strong halogen bonds with halogens in the crystal to pack the molecules tightly. This arrangement suppresses vibration and heat energy losses as the excited electrons fall back to the ground state, leading to strong phosphorescence.