I think that ultraviolet lights are also used by many airport agents in order to check the legitimacy of passports. It is used in many governmental departments as well. Having said that, sunlight also contains ultraviolet light. However, many departments and places have machines that emit ultraviolet lights and they use such kind of machines in order to detect counterfeit currency notes.
No, they don't use ultraviolet light to check passports in the airport. When was the last time you used a fight? There's a scanner where they place your passport and it's going to bring up everything in their system. They will need to look at your face to verify if you're the same person.