There is disclosed an ultraviolet radiation device. The device comprises a base portion, a plurality of semiconductor structures connected to the base portion and an ultraviolet radiation transparent element connected to the plurality of semiconductor structures. Preferably: (i) the at least one light emitting diode is in direct contact with the ultraviolet radiation transparent element, or (ii) there is a spacing between the at least one light emitting diode and the ultraviolet radiation transparent element, the spacing being substantially completely free of air. There is also disclosed a fluid treatment system incorporating the ultraviolet radiation device.
