White LED lighting, known as the fourth generation of lighting source, has the advantages of solidified, small size, low heat, low power consumption, long life, fast responding speed and environmental, and is expected to be widely applied in the fields of general lighting and backlight sources in the future. In particular, white LED lighting, since it satisfies the requirements of energy saving and environmental protection of the green lighting projects, it is expected to be widely used in the future. However, the light principle of semiconductor LEDs determines that the emitted light can only be monochromatic light, while visible sunlight is a colorful spectrum composed of the colors of red, orange, yellow, green, cyan, blue and purple. It is obvious that a semiconductor LED light source only having a monochromatic light is not suitable for the field of general lighting. If the semiconductor LED light source is required to use for the field of general lighting, the defect of monochrome light emitting must be overcome through the application of other technologies. White LED technology is a typical representative of the transformation of LED monochrome light; the purpose thereof is to make the LED light source close to the natural sunlight color, thereby making it useful in the field of general lighting.
Presently, in the manufacture of white LEDs at home and abroad, fluorescent material is a very important technology. White light is generated almost completely by using yellow phosphor combined with blue light. The property and preparation process of the fluorescent material directly affects the luminous efficiency, conversion efficiency, color coordination, color temperature and color-rendering property of the white LED. In actual application, the fluorescent material of the current white LED uses the amorphous phosphor as the main body. Generating a white light by the combination of single chip and phosphor is still the mainstream of the development of the general white light LED product. However, there are still several technical problems to be solved in the process of producing LEDs by using phosphor technology at the present stage of white LED: 1) the excitation efficiency and light conversion efficiency of phosphor are low; 2) the phosphor particles and dispersal uniformity issues are difficult to be effectively and completely solved; 3) phosphor lacks the red light-emitting component, it is difficult to produce a white LED with low color temperature and high color-rendering index; 4) the high light attenuation of phosphor leads to a shortened white LED life; and 5) phosphor has a poor physicochemical property that is unsuitable for the development requirement of the high-power LED. Under the influence of these problems of the properties of phosphor, the solving of the problems of white LED such as luminous efficiency, color-rendering property, life, high-power application and the like have encountered technical bottlenecks. This situation shows that the bottleneck of LED development increasingly highlighted that phosphor cannot meet the requirements of existing white LED and adapt to the future development trend of LED fluorescent lamp.
In the existing mixed LED white light technology, the white light is generated by a mixed light made by two or three complementary two-color LED light-emitting diodes or three primary color light-emitting diodes (LEDs). This technology generally uses only a simple mixing structure to obtain the mixed light, its color-rendering property is poor, and it is difficult to meet the practical requirements.
Meanwhile, with the acceleration of the speed of white LED lights coming to the market and the expansion of the application field, it exposed a major application problem of “visual defect” that still existed in the current white LED lights. This defect bears the brunt of the harm and influence to the human eye, attracting the attention and research of the customer and all sectors of the society.
In view of the above problems, the present invention is aimed to design a solar spectrum-like LED structure. A solar spectrum can be simulated by gathering and mixing LED light of different colors. The solar spectrum-like LED structure of the present invention overcomes the technical defect that the traditional white LED technology needs to use phosphor and can simulate a solar spectrum, while, at the same time, has good color-rendering property and visual effect, and can be widely applied in the fields of general lighting, agriculture, animal husbandry and new biological energy sources.