Light emitting diodes (LEDs) show high reliability, have low maintenance and repair costs due to long service life, and have low power consumption as compared to existing lighting instruments, and thus may greatly contribute to energy savings. Further, since it is easy to apply various designs and heat generation is low as a lighting device, an LED has very favorable conditions when the LED is used as illumination.
A fluorescent material used in a device including these LEDs, and the like is a material which converts light with a specific wavelength from various light sources into light with a desired wavelength, and is a core technology for manufacturing a white LED. In addition, the efficiency of the fluorescent material is an essential factor in driving a display and serves as a major parameter which is directly associated with the efficiency of a light source product including the display. Recently, a technology for implementing white light close to natural light as defined in CIE color coordinates, has been under development, and studies on a white LED device for emitting the white light have been actively conducted.
In general, a white LED is manufactured in a manner where one or more phosphors selected from phosphors of red, blue, yellow and the like are applied to blue or ultraviolet LED chips. In particular, when a red phosphor and a phosphor of another color are used in combination, in the case of a low half bandwidth of each phosphor, it is difficult to secure a sufficient color rendering index and there is a limitation in implementing desired natural white light.
Furthermore, since the red phosphor in the related art shows a relatively low half bandwidth, and shows a light emission peak at a wavelength band from 550 nm to 700 nm, it is difficult to show a sufficient color rendering property. Accordingly, in a white LED, there is a need for developing a red phosphor, which has excellent luminous efficiency and may implement a sufficient color rendering property.