A monolithic semiconductor light emitting device is described. The device includes an n-type region, a p-type region, an active region of a multiple quantum well structure comprising a plurality of alternating barrier and active layers interposed between the n-type region and the p-type region. The device emits multiple single-wavelength spectral distributions of ultraviolet light each having a peak wavelength of between 210 nm and 400 nm and/or a broadband spectral output having a wavelength of between 210 nm and 400 nm. Methods of making the device and lamps comprising the device are also described.