The Impact of Time and Temperature of Operation on the Characteristics of High-Power UVC LEDs and Their Disinfection Efficiency

Disinfection and sterilization based on the use of UVC radiation are the key technologies ensuring health and safety. Their reliability depends on assuring the effectiveness of the performed process. In recent years, the rapid development of LED sources emitting high-power radiation in the UVC range has been observed, and there is a growing interest in using them in a variety of smart applications, mostly because they are easy to control, do not contain hazardous substances, and there are prospects to increase their energy efficiency. However, the literature does not provide enough knowledge on the reliability of disinfection with high-power UVC LEDs. This research aims to present a methodology of linking the performance characteristics with assessing the forecasted changes in the disinfection efficiency of exemplary UVC high-power LEDs caused by thermal and temporal changes in their characteristics. Based on the performed degradation test, the impact of the temperature and time of operation of the high-power UVC LEDs on the effectiveness of disinfection was evaluated, and the required disinfection times for exemplary pathogens were calculated. The results reveal a strong influence of the time of operation of high-power UVC LEDs on the disinfection reliability caused by the degradation of their optical power but with a low significance of wavelength shift.