Electroluminescent devices from ionic transition metal complexes

Ionic transition metal complexes (iTMCs) are receiving increased attention as materials capable of yielding efficient electroluminescent devices with air-stable electrodes. The operational characteristics of these devices are dominated by the presence of mobile ions that redistribute under an applied bias and assist in electronic charge injection. This article reviews recent efforts in the field of iTMC devices: i) to understand their physics, ii) to improve their efficiency, colour, turn-on time and lifetime, and iii) to expose their potential applications.