Heavy Metal-Free Phosphorescent OLED

Melissae Fellet, Ars Technica:

Hiroki Uoyama, of Kyushu University in Japan, and colleagues designed a molecule that has a small energy difference between the singlet and triplet excitons. That way, triplet excitons can cross over to an excited singlet state and then relax to emit light.

What this means: More affordable than heavy metal-laden phosphorescent OLED with equivalent electricity to light efficiency of 19%.