Lanthanide complex-derived white-light emitting solids: A survey on design strategies

[Display omitted] •Lanthanide complexes offer facile routes and novel materials for solid-state white-light emitting applications.•The inherent challenge is to combine dichromatic or trichromatic light elements into a single phase and to modulate their emission intensities.•Single phosphor with energy transfer between the component emissive centers is a promising alternative to color mixing.•Modular synthesis and homogeneity in crystalline materials help to attain better efficiency and to derive structure-property correlations.•The hybrid counterparts enhance the prospect for better solution processibility to ensure real-world applications. Solid-state materials with tunable light emission characteristics offer an attractive prospect. Unique luminescence features of trivalent lanthanide (LnIII) ions—sharp characteristic emission in the visible and near-infrared (NIR) spectral regions, exceptional color purity, long luminescence lifetimes, high quantum yield and large Stokes shifts—afford them as promising white-light source materials. The review provides an overview of the recent developments in the Ln- complex-based solid-state white-light emitters with particular emphasis on different design strategies and photoluminescence features to augment the foundations of factual knowledge further. The approaches adopted in the lanthanide coordination complexes—logical codoping of LnIII in various compositions, lanthanide encapsulation in MOF pores, infinite coordination particles, and lanthanide incorporated composites—to attain tunable white-light emission, will be discussed. The pros and cons of different adopted strategies in term of further processing of the materials into real-world applications as well as the imminent challenges are also reviewed and put in prospect.