Luminescent materials are divided into self-luminous type and light storage type. The basic component of self-luminous luminous materials is radioactive substances, which do not need to absorb energy from the outside and can emit light continuously, not only at night but also during the day. Because it contains radioactive substances, its use is greatly restricted, and the disposal after treatment is also a big problem. Light-storing luminescent materials rarely contain radioactive substances, and there are no restrictions on their use, but they can only emit light by absorbing external light energy, and enough light energy must be reserved to ensure that they always emit light. Another defect of light storage luminescent materials is insufficient brightness. For example, zinc sulfide was used as an afterglow phosphor in the past, but the luminescence time was too short and the brightness was not enough. So later, a radioisotope giant 147 was mixed, and the luminous effect was ideal, but the intervention of radioisotopes. Does not meet the requirements of environmental protection.
Although there are pollution-free luminous materials, the patent right belongs to Japan and the cost is very high, so the cheap luminous ornaments on the market should all belong to the former.