decorative gravels Afterglow phenomenon

If the fluorescent material contains some trace impurities, and these levels of impurities located in the forbidden band, the equivalent of trap levels, 

After being excited from the valence band into the conduction band electrons, will fall into the trap levels. Because these are captured by the trap levels must first excited electronic trap levels out after the transition back into decorative gravels‍ the conduction band to the valence band, so they are incident photon excitation luminescence will be delayed for some time, the emergence of the so-called afterglow phenomenon. 

Afterglow generation principle 

Afterglow generation principle 

Long-lasting and can be divided into short afterglow afterglow, they are determined by the delay time. 

Is the photoluminescent material in the light emitting material (usually ultraviolet light, infrared light and visible light) emitting excitation irradiation. Relaxation time classified according to light, the photoluminescent material can be divided luminescent sheets‍ into two types of fluorescent materials and phosphorescent materials. They correspond to the above short and long afterglow afterglow. 

Photoluminescence mainly three-step process: 

1, the absorption of a photon; 2, the laser can be transferred to the fluorescent centers; 3, the radiation emitted by the fluorescent centers. 

Photoluminescent material is mainly used for display, imaging, lighting and everyday life. In everyday products, such as washing brighteners, fluorescent paint, fluorescent cosmetics, and so the use of the fluorescent dye a fluorescent material. Some lamp phosphor photoluminescent signs‍ materials are phosphorescent material, which can be made with high efficiency and high color rendering fluorescent lamps.