The client is involved in the design of the plan, Misunderstanding common transparent plastics such as acrylic in visible light scheme design, It can also be used as UVC-LED The light window, The sterilization effect is zero. This situation is not uncommon. The concept of borrowing key energy, C-H and C-O The key is in UVC and UVB The absorption coefficient in the ultraviolet band is very high, So thin plastic can absorb almost all of the deep ultraviolet radiation. The absorption edge of ordinary polystyrene and acrylic is 385nm left and right, at 275nm The transmittance at this point is already equivalent to zero.
What kind of material should be used for deep ultraviolet LED Where is the light window? Sapphire is deep ultraviolet LED The substrate, It is also the light-emitting surface of the chip, So it can serve as a light window, But the material and processing costs are high. There are many types of quartz, Three common types of optical glass, JGS123, suggestion 275nm of UVC-LED can be used JGS2 Quartz specifications, 265nm Even the following LED, Need to adopt JGS1 Quartz or sapphire. This also applies to the lens material used in the packaging of lamp beads.
The following figure shows the report of the sterilization test conducted on the customer's product, The sterilization rate is very low.
After receiving customer feedback, our company FAE First, use an optical power density meter to test the optical power density of the customer's product, as shown in the figure:
After testing, it was found that the optical power density is very low, Let's take another look at the translucent window, The customer used acrylic sheet, Therefore, it leads to a low sterilization rate. So what kind of material should be used to make deep ultraviolet LED Where is the light window? Sapphire is deep ultraviolet LED The substrate, It is also the light-emitting surface of the chip, So it can serve as a light window, But the material and processing costs are high. There are many types of quartz, Three common types of optical glass, JGS1/JGS2/JGS3, suggestion 275nm of UVC-LED can be used JGS2 Quartz specifications, 265nm Even the following LED, Need to adopt JGS1 Quartz or sapphire.