Light‐emitting electrochemical cells (LECs) are solid‐state lighting devices that convert electric current to light within electroluminescent organic semiconductors, and these devices have recently attracted significant attention. Introduced in 1995, LECs are considered a great breakthrough in the field of light‐emitting devices for their applications in scalable and adaptable fabrication processes aimed at producing cost‐efficient devices. Since then, LECs have evolved through the discovery of new suitable emitters, understanding the working mechanism of devices, and the development of various fabrication methods. LECs are best known for their simple architecture and easy, low‐cost fabrication techniques. The key feature of their fabrication is the use of air stable electrodes and a single active layer consisting of mobile ions that enable efficient charge injection and transport processes within LEC devices. More importantly, LEC devices can be operated at low voltages with high efficiencies, contributing to their widespread interest. This review provides a general overview of the development of LECs and discusses how small molecules can be utilized in LEC applications by overcoming the use of traditional lighting materials like polymers and ionic transition metal complexes. The achievements of each study concerning small molecule LECs are discussed.

Organic luminescent materials with leveraging properties have attracted urgent demand for their commercial application in lighting devices. In this work, two organic emitters PITP and PITT based on thiophene linked...

The future artificial lighting devices ought to be efficient, economical, and environmentally benign that are free from rare metals like iridium. In this regard, we report a step towards this...

Two new ionic green-emitting D−A-type emitters were designed and synthesized with good yields. The potential of diphenyl triazine as an acceptor was utilized here to generate efficient green emitters by coupling with two derivatives of imidazole donors. The synthesized emitters exhibited excellent solubility, high luminescence in solution and solid state, high thermal stability, and good film-forming abilities. Bright green emissions were achieved by applying these emitters in a light-emitting electrochemical cell (LEC) device stack. It is noteworthy that these emitters can generate excellent light emissions without additional ions or hosts. Both emitters presented similar photophysical properties. However, the phenanthroimidazole-triazine (PhTz)-based emitter performed better in devices compared to the diphenylimidazole-triazine (BzTz)-based emitter. The nondoped LEC device with PhTz and BzTz as active materials sandwiched between air-stable electrodes exhibited green emission at 505 and 499 nm with Commission Internationale de I'Eclairage coordinates of (0.28, 0.54) and (0.27, 0.52), respectively. These triazine-based devices showed a maximum brightness of 1453 and 1048 cd/m 2 for PhTz and BzTz, respectively. The maximum current and power efficiencies were noted to be 2.83 cd/A and 0.63 lm/W, respectively, for the PhTz-based device and 1.72 cd/A and 0.325 lm/W, respectively, for the BzTz-based device.