Advancements in UV-C LED technology: improving external quantum and system efficiency (Invited Paper)

The use of ultraviolet (UV-C) light for disinfection has been a well-established practice for many years. In recent years, the development of UV-C LED technology has provided a promising alternative to traditional low pressure mercury lamps. One of the most anticipated parameters of UV-C LED technology is the external quantum or wall plug efficiency. This paper reviews the recent progress and prospects of UV-C LED development, focusing on wall plug efficiency and lifetime at different wavelengths which are suitable for germicidal applications. The robustness of UV-C LED packages is also improving significantly and even tests according to the automotive AEC Q102 specification have been passed successfully. Beyond the pure LED parameters there are further factors and features that affect the system efficiency of UV-C LED based disinfection devices. Examples are demonstrating the big differences in system efficiency between conventional lamp and LED based systems. The big steps in development of UV-C LED during the last years justifies an optimistic outlook to target a replacement of conventional low pressure mercury lamps in the coming years.