Polarization effect on the Auger recombination coefficient in single InGaN/GaN quantum wells

We investigate the effect of polarization on the direct Auger recombination rate in In_xGa_1-xN/GaN single quantum wells by full Brillouin zone calculations within the framework of the empirical pseudopotential linear combination of bulk bands method for the electronic structure description. It is compared the Auger coefficients as a function of alloy composition for realistic and artificial polarization-free quantum wells. The results reveal that the polarization fields strongly enhance the Auger recombination rate for the alloy compositions x < 0.4 while for highly alloyed quantum wells (x > 0.5) the effect of polarization is weak. Unlike the bulk case, the calculated Auger recombination coefficient in the quantum wells corresponding to the visible spectrum optical transition energies demonstrates a weak compositional dependence with a trend to decrease from 2.7 × 10⁻¹⁸ cm⁴s⁻¹ (blue emitting quantum wells) to 2.5 × 10⁻¹⁹ cm⁴s⁻¹ (red emitting quantum wells).