Earth-abundant transition metal complexes in light-emitting electrochemical cells: successes, challenges and perspectives

Abstract

Light-emitting electrochemical cells (LECs) are an attractive technology in the field of solid state light devices (SSLDs) as their simple architectures allow the preparation of cost-effective lighting devices. Consequently, low-cost and sustainable emitters are highly desirable. Transition metal complexes are attractive in this field as they have been proved to possess compatible optoelectronic properties. Nowadays, the best emitters are based on platinum and iridium class metals, which is a limitation for industrial production. Due to this concern, researchers have turned their attention to Earth-abundant metal complexes. However, the abundance of these metals should not blind us to a consideration of their cost. Herein, the photophysical properties of the most interesting Earth-abundant metal complexes and their performance in LECs are put into context with respect to their real cost based on their metal precursors, revealing some surprises.