Light-emitting diodes (LEDs) are
attracting considerable attention
around the world. Phosphor materials, as crucial color-converted components,
play central roles in LED development. The demands for phosphor materials
have become increasingly stringent over the past decades, from high
brightness to narrowband emission or function-dependent spectrum engineering.
Although substantial progress has been made for currently developed
phosphor materials, simultaneously satisfying all requirements for
high-level applications remains challenging. In this review, we aim
to provide a comprehensive understanding of the development of phosphor
materials in different generations and to elucidate the key designed
mechanisms concerning the activators and the host structures to fulfill
the aforementioned aspects. We highlight the developments in phosphor
materials through the classification of demands for high luminescence,
high thermal stability, narrowband emission for high color gamut,
and broadband emission for near-infrared. We also focus on elucidating
the key designed mechanisms of phosphor materials in different generations.
Furthermore, future perspectives about micro-LED applications and
nanoluminescent materials are provided. This study opens up an avenue
for designing the luminescent materials of the future.