Carrier screening effects on intersubband nonlinear optical rectification in wurtzite InGaN/GaN coupling quantum wells

Carrier screening effects on an optical rectification (OR) susceptibility of InGaN/GaN coupling quantum well (CQW) structures are theoretically investigated by using effective mass theory. The intersubband (ISB) transition energy E-21 is shown to be strongly affected by the carrier screening. It has the value of about 0.1-0.13 eV, which is comparable to that (similar to 0.12 eV) observed in GaAs/AlGaAs system. The peak energy of the OR coefficient is redshifted greatly by the carrier screening effect with increasing carrier density. Also, the peak intensity of the OR coefficient rapidly increases with increasing carrier density because the OR coefficient is proportional to carrier density.