UV LEDs: A Cool Alternative to Arc Lamps

Emerging UV light sources has more potential applications and more efficient.

LEDs are efficient. The Nobel Prize committee understands this; in December in Stockholm they present the 2014 Nobel Prize in Physics jointly to Isamu Akasaki, Hiroshi Amano and Shuji Nakamura for the invention of blue light-emitting diodes. These blue LEDs enabled the development of bright and energy-saving white light sources. At first these white LED bulbs tended to be harsh and expensive and were only practical for high power consumption applications where their cost could be offset by their energy savings such as highways or parking lots.

Recently, however, consumers have been getting in on the energy savings. White LED lamps have come down in price and increasingly are becoming a practical option for consumers. Improvements in color temperature (how “warm” a light looks) are speeding the switch to LED lighting from incandescent, halogen and fluorescent bulbs. An IHS Technology report pegged the LED component market at $17.7 billion in 2013. and estimated it will grow steadily over the next several years.

The impact of this switch is significant. The U.S. Energy Information Administration estimates that 12% of the total U.S. electricity consumption is used for lighting. Some 40% of that consumption corresponds to residential lighting where LEDs are just being adopted. The Nobel Committee explicitly recognized the transformative impact of white LEDs as the motivation for making this year’s award.

So with the white LED bulb market in full swing, what is next potential market for LEDs? The answer may be ultraviolet (UV) applications. Here's why.

Arc lamps are inefficient. These traditional sources of UV light are slow to heat up, slow to cool down, have short lifetimes and give off a lot of heat. The heat is especially a problem in UV curing applications where it can affect the materials being cured.

The market for UV light sources, although only a fraction of the visible lighting market, is still estimated to be in the hundreds of millions of dollars across a number of industries. With potential applications in water and air purification, currency validation, fluorescence, sensing, medical instruments, 3D printing and UV curing, there is plenty of opportunity for a better UV light source. LED manufacturers have realized and have been investing in UV LED R&D over the past decade.

Since their introduction in the 1960s, LEDs' biggest selling point has been their energy efficiency. In the case of the UV LED market, the selling point is more about the precision of the spectrum they can provide. Materials can be highly specific in the kind of UV they need in order to work. Whether it’s curing or fluorescence, spectral precision is an important factor and UV LEDs are an alternative to wide spectrum arc lamps.

The smaller size possible with UV LEDs opens the door to still more applications. Handheld UV light sources could be used from surgical devices to 3D pens to flaww detection. As technologies continue to emerge that exploit the UV portion of the spectrum the UV light source market has the potential for considerable growth.

Arc lamps, like most bulb technologies, have been the industry standard light source until recently. However, the path of future innovation increasingly appears to be lit by LEDs.