Bulk- and Nanocrystalline-Halide Perovskite Light-Emitting Diodes

Halide perovskites are a class of solution-processable semiconductors, a new member of the photovoltaics (PVs), light-emitting diodes (LEDs), and lasers. Low-cost methods can synthesize highly defect-tolerant halide perovskites. These perovskites exhibit unexpectedly high performance in charge/exciton transport and luminescence efficiency. Halide perovskite can form itself into versatile structures and compositions. These various perovskites cover the entire visible spectrum, plus the near-infrared (NIR). Their color purities are naturally saturated, with small full width at half maximum (FWHM) of the emission spectrum comparable to the best-performing quantum-dot (QD) emitters. Device work in perovskite light-emitting diodes (PeLEDs) has proved that their efficiency is already comparable to other high-performance light-emitting materials, such as organic semiconductors (OSCs) and inorganic QDs. In this chapter, we introduce the basics of perovskite materials/LEDs, review the start-of-the-art device work, and discuss the prospects of this field.