Interplay of screening and band gap renormalization effects in near UV InGaN light emitting diodes

The impact of the barrier composition on the shift of the luminescence peak wavelength of ultraviolet (UV) emitting InGaN quantum wells was investigated theoretically. Depending on the strain and the aluminum and indium mole fractions in the barriers, a blue, a red or almost no shift was obtained with increasing carrier density which can be attributed to different degrees of compensation of the screening of the internal electric field by band gap renormalization. The electroluminescence of fabricated light-emiting diodes exhibited the predicted behaviour in dependence on the injection current.