Light emitting systems are disclosed. The light emitting system includes an electroluminescent device that emits light at a first wavelength. The light emitting system further includes an optical cavity that enhances emission of light from a top surface of the light emitting system and suppresses emission of light from one or more sides of the light emitting system. The optical cavity includes a semiconductor multilayer stack that receives the emitted first wavelength light and converts at least a portion of the received light to light of a second wavelength. The semiconductor multilayer stack includes a II-VI potential well. The integrated emission intensity of all light at the second wavelength that exit the light emitting system is at least 10 times the integrated emission intensity of all light at the first wavelength that exit the light emitting system.