The present invention relates to a process for manufacturing an optoelectronic device, wherein a layer of a formulation containing a silazane polymer and a wavelength converting material is applied to an optoelectronic device precursor, precured by exposure to radiation and then cured. There is further provided an optoelectronic device, preferably a light emitting device (LED) or a micro-light emitting device (micro-LED), which is prepared by said manufacturing process.