Non-polar III-nitride heterostructures

III-nitride quantum heterostructures have gained tremendous interest due to the feasibility of attaining visible and ultraviolet light emission. However, the internal quantum efficiency of such optical devices is limited by built-in electrostatic fields which induce a separation of the electron and hole wavefunctions. The reduced wavefunction overlap translates to a decrease in the radiative transition probability. Furthermore, a redshift of the emission wavelength occurs due the quantum-confined Stark effect. Both these effects are a consequence of the large spontaneous and piezoelectric polarization along the growth axis (which is the singular polar axis) in wurtzite III-nitride heterostructures.