What is UV LED?
Understand the principle of UV LED
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Introduction to UV LED
From principle to application：analyzing UV LED,high-power features, and differences from mercury lamps.
UV LED (Light Emitting Diode) is a type of LED light source that emits ultraviolet light.
Standard household LED lights are designed for everyday illumination and do not emit significant amounts of ultraviolet (UV) radiation. Therefore, they do not cause tanning or other skin damage.
LED lighting is widely used across various fields due to its high efficiency, low energy consumption, and long lifespan. Common applications include home lighting, plant grow lights, and black lights.
Development of UV LEDs
𖡡 1993
Shuji Nakamura, working at Nichia Chemical in Japan, successfully incorporated nitrogen to develop blue LEDs based on wide-bandgap semiconductor materials—gallium nitride (GaN) and indium gallium nitride (InGaN). These LEDs became commercially viable and were widely adopted in the late 1990s.
𖡡 2001
Kaufmann et al. proposed the concept of using UV LEDs to excite red, green, and blue phosphors to generate white light.
𖡡 Since 2012
Several companies began launching experimental samples or small-scale commercial UVC LED products that demonstrated effective sterilization performance.
𖡡 Between 2014 and 2015
With improvements in manufacturing processes and production capacity, UVC LEDs gradually started to be applied in water treatment, air purification, and surface disinfection.
𖡡 After 2020
The COVID-19 pandemic drove a surge in demand, leading to rapid expansion of the UVC disinfection market.
Comparison Between LED and UV LED
項目 | LED（發光二極體） | UV LED（紫外線發光二極體） |
|---|---|---|
Visible Effect | Visible to the human eye (used for illumination or color display) | Invisible to the human eye (but capable of triggering chemical reactions or sterilization effects) |
Applications | Lighting, Display, Decoration | Disinfection, Curing, Aesthetic Treatments, Inspection |
Type of Light Emitted | Visible light (red, green, blue, white, etc.) | Ultraviolet light (UVA, UVB, UVC) |
Definition | Common light sources in daily life, such as light bulbs, television screens, and car headlights, are primarily used for ambient lighting or color display. | A type of light source that emits ultraviolet (UV) light. Its main purpose is not illumination, but rather functional applications in specific environments. |
Classification and characteristics of UV LED
UV LEDs are categorized by wavelength into UVA, UVB, and UVC types.
Main wavelengths: 340 nm / 365 nm / 375 nm / 385 nm / 395 nm / 405 nm
Main wavelengths: 295 nm / 310 nm / 325 nm
Main wavelengths: 255 nm / 265 nm / 275 nm / 280 nm
UVA LEDs are available across the entire wavelength range. Since the wavelength can be adjusted during epitaxial growth, it is not limited to the values listed above.
Here are some points of comparison between UV LED and UV mercury lamps:
Difference between UV LED vs UV mercury lamps
1. Wavelength selectivity
UV LED has a wide range of wavelength options due to its characteristics,
while UV mercury lamps commonly come in only two wavelengths, 254nm and 365nm.
2. Switching time
UV LED can turn on and off instantly, reducing power waste when not in use.
UV mercury lamps need to preheat before use.
3. Radiant heat
UV LED is a cold light source with low radiant heat, making it suitable for curing heat-sensitive materials.
UV mercury lamps emit radiant heat, which may heat up the materials being irradiated, making them unsuitable for curing heat-sensitive materials.
4. Thermal Management Requirements
UV LED require thermal management design, and as power increases, the demand for heat dissipation also rises;
UV mercury lamps generate more heat, but thermal management technologies are more mature.
5. life-time
The service life of UV LED can reach 5,000-10,000 hours,
while UV mercury lamps have a shorter lifespan, typically 1,000-3,000 hours.
6. Size
UV LED is very small, making it suitable for use in many space-restricted environments, and can be assembled in various shapes to meet different applications.
UV mercury lamps are mostly in the form of tubes and have a larger size, making them less versatile in application.
7. Structural strength
UV LED is resistant to collision and falling,
while UV mercury lamps are made of quartz tubes and are easy to break.
8. Directionality
UV LED emits light in one direction and can change the angle through different optical lenses to concentrate most of the energy where needed.
UV mercury lamps emit light in 360 degrees, resulting in a lot of wasted energy.
9. Optical Efficiency
UV LED have high efficiency, with electrical energy directly converted into light of a specific wavelength;
UV mercury lamps have lower efficiency, with a large portion of energy converted into heat.
10. Environmental friendliness
UV LED does not contain mercury, making it the preferred choice due to its environmental friendliness.
UV mercury lamps contain mercury and will gradually be phased out due to the Minamata Convention on Mercury.
11. Safety
UV LED emit a single wavelength, offering higher safety for specific applications;
UV mercury lamps emit multiple wavelengths, which may cause unnecessary ultraviolet exposure.
12. Application Scenarios
UV LED are used in disinfection and sterilization, UV curing, inspection, medical treatment, and plant lighting, etc.;
UV mercury lamps are used in disinfection and sterilization, photochemical experiments, spectral calibration, UV curing, etc.
13. Operating Costs
UV LED consume less power and have low maintenance costs;
UV mercury lamps consume more power and require frequent lamp replacements, resulting in higher maintenance costs.
Definition and characteristics of high power UV LED
According to the general definition in the LED industry, an LED with an input power greater than 1 watt is considered a high-power LED.
For UVA LEDs, the voltage is typically between 3.5V-4V, so an input current of 350mA or higher can be considered a high-power UVA LED.
For UVB and UVC LEDs, the voltage falls between 5V-7V, and an input current of 150mA or higher can be considered a high-power UVB/UVC LED.
Characteristics and Challenges of High-Power UV LEDs
High Thermal Dissipation Requirements
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At high power input levels, the LED chip heats up rapidly.
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It must be equipped with a heatsink, and in some cases, forced air cooling (fan) or liquid cooling systems are required.
Impact of Temperature on Lifespan
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The junction temperature (Tj) of the LED chip is typically kept below 120°C.
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To ensure stability and long lifespan, it is recommended to maintain the chip temperature below 80°C.
Reliability Design
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Insufficient heat dissipation can lead to severe light decay, shortened lifespan, or even device failure.
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Experienced engineers are needed to conduct thermal simulations to ensure the performance and stability of UV LEDs under high-power operation.
Violumas products have the best thermal dissipation on the market with our patented 3-PAD Flip Chip LED and Pillar MCPCB. We offer reliable solutions that can withstand extreme environments and suboptimal conditions by optimizing heat flow from the LEDs.
With 3-PAD we proudly offer the most powerful & reliable UVC LED solutions on the market today.
Violumas offers full-spectrum UV LED products, including chips, packaging, and modules.
They meet the needs of various industries.
>>Contact us for professional UV LED solutions and technical support.