What kind of harm will the color LED display appear at the high temperature line?

The high temperature of the LED display, the LED display is very picky about the ambient temperature. In theory, it is about 25 degrees Celsius at room temperature, and its working conditions are optimal. But in reality, the ambient temperature of an outdoor display is quite complex in the application. The maximum temperature in summer may be higher than 60 degrees Celsius, and the lowest temperature in winter may be lower than -20 degrees Celsius. If the temperature is too high, the LED display will be completely destroyed. The life of an LED display is its light decay, which is a long time, and the brightness is getting lower and lower until it is finally extinguished. The time that the luminous flux of an LED display is attenuated by 30 is usually defined as its lifetime. The reason why the LED display emits light is as follows:

 

Defects in the LED display chip material will proliferate rapidly at higher temperatures. - Reproduction until it invades the illuminating area, forming a large number of non-radiative recombination centers, which seriously reduces the luminous efficiency of the LED display. In addition, under high temperature conditions, micro-defects in the material and rapidly expanding impurities from the interface and board will also be introduced into the illuminating region, forming a large number of deep layers, which will also accelerate the light attenuation of the LED display device. The transparent epoxy resin denatures at high temperatures. - Yellowing will affect its light transmission properties. The higher the operating temperature, the faster the process proceeds. This is another major cause of LED display attenuation. The light attenuation of LED display phosphors is also the main cause of LED display light attenuation, because the phosphors are very attenuated at high temperatures.
 

 

An increase in temperature will reduce the luminous efficiency of the LED display. The causes of the temperature effect of the LED display include the following aspects: an increase in temperature, an increase in the concentration of electrons and holes, a decrease in the band gap, and a decrease in electron mobility. Will decrease. As the temperature increases, the likelihood of recombination of electrons and holes in the well is reduced, resulting in non-radiative recombination (heating), thereby reducing the internal quantum efficiency of the LED display. The increase in temperature causes the blue peak of the chip to move in the long-wave direction, which causes the emission wavelength of the chip to be mismatched with the excitation wavelength of the phosphor, which also causes a decrease in external light extraction efficiency. White LED display. As the temperature increases, the quantum efficiency of the phosphor decreases, the luminescence decreases, and the external light extraction efficiency of the LED display panel decreases. The properties of silica gel are greatly affected by the ambient temperature. As the temperature increases, the thermal stress inside the silica gel increases, causing the refractive index of the silica gel to decrease, thereby affecting the light efficiency of the LED display.