A high efficiency microcavity light emitting diode comprises a stack of AlxInyGa1-x-yN layers, where 0≦x, y, x+y≦1, with each layer having a high crystalline quality. The stack has a uniform thickness less than 6λ/n, with an active layer centered approximately (2i+1)λ/(4n) from a reflective electrical contact, where λ is the peak emission wavelength, n is the index of refraction at the peak emission wavelength, i is an integer, and each layer within the stack has a dislocation density below about 105 cm−2.