Phosphor materials are an integral and important part in the white light generation in LEDs and have participated in the global warming reduction significantly. In this chapter, the authors focus on different types of phosphor materials belonging to a family of apatites, fluoroapatites, silicates, oxides, phosphates, and borates with different crystal structures. The detailed investigations on their crystal chemical structure, synthesis, and photoluminescence properties are briefly discussed. The improved optical properties make the phosphor potential candidate for smart panel displays and white light emitting diodes (including solid state lighting). The crystal structure has a great influence on the chemical and luminescence properties of any phosphor; hence, a great change of activator ion (Eu 2+ , Ce 3+ , Mn 2+ , and Tb 3+ ) concentrations can be achieved in the phosphor performances. The chapter correlates the structure-compositions-property of the phosphor materials with special emphasis on white LEDs. © 2018, IGI Global.