preferably the whole visual spectrum especially in the range from 400 nm to 700 nm or at least in the range from 420 nm to 600 nm a peak center of the second wavelength is preferably between 450 nm and 480 nm the inventive phosphor can be well excited under uv light irradiation and emits blue or white light in addition the phosphor shows high thermal stability which is comparable to that of yag ce 3 phosphor due to the described luminescence characteristics the phosphor according to the present invention can be used as a radiation converter for the transformation of uv 250 nm to 420 nm into a longer wave visible light that well be emitted by the phosphor preferably in blue to orange spectral region the inventive phosphor can be used in light sources e g in white light emitting light sources alternatively this phosphor can be used in photovoltaic cells in greenhouse foils or in greenhouse glasses in these applications the light of the sun forms the radiation in the first wavelength range of the electromagnetic spectrum the radiation emitted by the phosphor will be directed to the photovoltaic cells and to the plants in the greenhouse respectively the inventive light source comprises an inventive phosphor and a radiation emitting element that emits radiation in the first wavelength range of the electromagnetic spectrum the phosphor converts the emitted radiation of the first wavelength range into the radiation of the second wavelength range the radiation emitting element acts as excitation source for the phosphor the light source emits at least the radiation in.