Solid-state lighting (SSL) is a type of lighting that uses semiconductor light-emitting diodes (LEDs), organic light-emitting diodes (OLED), or polymer light-emitting diodes (PLED) as sources of illumination rather than electrical filaments, plasma (used in arc lamps such as fluorescent lamps), or gas. Prof. Hashem Shahroosvand from Molecular Engineering of Advanced Functional Materials (GMA), University of Zanjan, Iran and his research team has discovered polypyridyl ligands as a versatile platform for solid-state light-emitting devices (SSLED). One of the major scientific breakthroughs that have impacted on everyday human lives on a global scale was the discovery of solid-state lighting (SSL). SSL is based on the concept of electroluminescence, where light is produced by the radioactive deactivation of excitons generated by efficient electron-hole recombination in the bulk of semiconducting materials [ 1, 2 ]. Hence, in contrast to traditional lighting devices where light is a by-p...