  In recent years, the field of metal-halide perovskite emitters has rapidly
emerged as a new community in solid-state lighting. Their exceptional
optoelectronic properties have contributed to the rapid rise in external
quantum efficiencies (EQEs) in perovskite light-emitting diodes (PeLEDs) from
<1% (in 2014) to approaching 30% (in 2023) across a wide range of wavelengths.
However, several challenges still hinder their commercialization, including the
relatively low EQEs of blue/white devices, limited EQEs in large-area devices,
poor device stability, as well as the toxicity of the easily accessible lead
components and the solvents used in the synthesis and processing of PeLEDs.
This roadmap addresses the current and future challenges in PeLEDs across
fundamental and applied research areas, by sharing the community's
perspectives. This work will provide the field with practical guidelines to
advance PeLED development and facilitate more rapid commercialization.
