The low-pressure mercury lamp is almost dead. Long live the UVC LED!

Used for more than 40 years for their germicidal effects, systems based on low-pressure mercury lamps (LP-Hg lamps) for surface, air, and water disinfection will gradually disappear in favor of UVC LEDs. The Minamata Convention on Mercury (a global treaty that aims to protect human health and the environment from the harmful effects of mercury), future regulations, and lack of competing technology should allow UVC LEDs to take over the market, just as white light LEDs did a few years earlier in the general lighting segment. The adoption of this technology for this purpose is, therefore, no longer a question of “if” but “when.”

That is the point of the report, UVC LED Beyond COVID-19: Performance Analysis and Comparison, in which PISÉO, Yole Group’s partner, delivers a clear and relevant picture of past and future performance and cost trends based on a comparative analysis of an extensive list of 160 LEDs currently on the market. Strategy and market positioning of the major players are presented. In addition, key factors still regarded as hindrances to the full adoption of this technology are analyzed in detail.

As with white-light LEDs, PISÉO considers wall-plug efficiency as the champion parameter that will, at a specific level, help bring LP-Hg lamps to an end. However, for the time being, most UVC LED WPEs are in the range of 1 – 4%, too low to compete with LP-Hg lamps which have an efficiency of around 30%.

Nichia provides an LED with WPE > 5%, although for a 280 nm wavelength which has a lower germicidal effect. Bolb Inc. and ams OSRAM fare well with an efficiency > 5.5% at 265 nm, the optimum wavelength for this application. The interesting fact remains that the global leader in optical solutions introduced its product, which bears an uncanny resemblance to Bolb’s design, a few months after acquiring 20% of Bolb Inc., leaving no doubt as to the device’s origin. Still, with its patented transparent chip UVC LED structure, Bolb Inc., the newcomer, is ahead of the competition with four products featuring between 5.5 and 6.4% efficiency.

Despite a significant decrease between 2016 and 2021 (factor of 200), the cost of UVC LEDs remains high compared with LP-Hg lamps ($0.05/mW versus ~$0.002/mW). However, it is approaching a sufficiently high level to intensify interest in bringing the product to the market.

Although already superior to LP-Hg lamps (12,000 h against 8,000 h), the lifetime remains a parameter to be improved to offset the purchase cost by a longer operating time and, therefore, a lower maintenance cost.

Holding all the cards, PISÉO considers that UVC LEDs could feature a WPE equivalent to that of LP-Hg lamps and a lifetime equal to that of white light LEDs (50,000 h) by 2028.

After a few years of timid achievements, the COVID-19 pandemic has driven optical players out of hiding. Many announcements have been made recently. Last month, Bolb Inc. boasted a WPE of 8.3% on UVC LED prototypes, while Crystal IS claimed a projected L70 lifetime value of over 25,000 hours for its latest generation product. Samsung, which has recently entered the market, could show some exciting achievements this year. According to PISÉO, more announcements are expected, confirming the intense activity in the field.

Yole Group and PISÉO teams invite you to follow the technologies, related devices, applications, and markets on www.yolegroup.com.

Stay tuned!