12 - Applications of quantum dots in light-emitting devices

Abstract

This chapter offers a brief outlook of the recent progress in the field of quantum dot (QD) light-emitting diodes (QLEDs). The external quantum efficiency has achieved a milestone of 30% on the silver jubilee of QLEDs from <0.01% at the time of its inception. The underlying factors are the high luminescence efficiency and unique size tunable emission of solution-processable semiconducting QDs that apply in energy efficient, high color quality thin-film displays, and solid-state lighting. To understand the requirements for high-quality lighting completely, a short overview of the field of solid state lighting and color conversion phenomena is presented in the first section. The advantages and applications of QDs in displays and lighting are followed in this section. The second section is about the basic concepts and mechanisms involved in QLEDs. The current competent devices with variety of state-of-the-art measures and the chronological steps taken for significant improvements in efficiency are discussed in the third section. This section provides a glimpse of diverse type and range of novel device designs utilizing all-QDs including alloyed, doped, and core/shell QDs, perovskite QDs, plasmonic enhancements, toxic and heavy metal free, ternary and quaternary hybrid compounds, carbon, graphene and silicon QDs, and the wide range of highly promising NIR QDs. In addition, the importance of QD surface treatments, recent advances in charge transport layers, blocking layers, and nanostructured photoanode fabrication are also highlighted. Finally, the key scientific and technological challenges facing commercialization of QLEDs are addressed and offer out-look for on-going strategies to overcome these challenges followed by future ventures of this technology.