Phosphor-converted white-light-emitting diodes (PC-WLEDs) are the main devices behind solid-state lighting (SSL) for both indoor and outdoor lighting, or backlight of liquid-crystal displays (LCD). Nonetheless, despite the current maturity of such devices, some concerns on spectral distribution, reliability, and color qualities of WLEDs for lighting, or even the enhancement of the color gamut of backlight WLEDs still need to be addressed while those achievements lie in the design of high-efficient downshifting converter phosphors featuring thermally-stable luminescence. Additionally, the application of PC-WLEDs in indoor farming and in phototherapy have also been envisaged, however, to fulfill such needs, LEDs are far away in performance compared to those lamps used in lighting. In this context, herein, we overview the state-of-the-art of phosphors able to be used as downshifting converter coatings in LEDs for application in lighting, phototherapy, indoor farming, and phototherapy as well as issues to be overcome and means to achieve it. The main classes of materials discussed here include Eu³⁺, Eu²⁺, Ce³⁺, Mn²⁺ and/or Mn⁴⁺-activated inorganic phosphors, quantum dots, and complexes. Finally, several figures of merit able to qualify the device performance considering photometry, colorimetry, and light impact on human or plant physiology are presented.

磷光转换的白光发光二极管（PC-WLED）是固态照明（SSL）背后用于室内和室外照明或液晶显示器（LCD）背光的主要设备。尽管如此，尽管这种设备目前已经很成熟，但是对于照明用WLED的光谱分布，可靠性和颜色质量，甚至背光WLED色域的增强，仍需要解决一些问题，而这些成就在于LED的设计。具有热稳定发光的高效降档转换磷光体。另外，也已经设想了PC-WLED在室内耕作和光疗中的应用，但是，为了满足这种需求，与照明中使用的那些LED相比，LED的性能相差甚远。在此上下文中，我们概述了可用作照明，光疗，室内农业和光疗中的LED的降档转换涂层的最先进的荧光粉，以及需要克服的问题和实现它的方法。这里讨论的主要材料类别包括Eu³⁺，Eu 2 ⁺，Ce ³⁺，Mn ²⁺和/或Mn ⁴⁺活化的无机磷光体，量子点和配合物。最后，介绍了能够通过光度法，比色法以及光对人或植物生理的影响来鉴定设备性能的几个品质因数。