Intrinsic electric fields in N-polarity GaN/AlxGa1-xN quantum wells with inversion domains

[摘要] GaN/AlGaN quantum wells (QWs) of dominant N polarity with inversion domains (IDs), grown by molecular-beam epitaxy, have been studied. Two-band photoluminescence (PL), with the lower-energy band and an additional absorption edge related to the IDs, is observed in these QWs due to a difference in strain, electric field, and well width in the regions of different polarities. A time-resolved PL study reveals additionally strong inhomogeneity of the electric fields among the IDs. The intrinsic electric fields in the structures are relatively small-their maximal estimated value of 180 kV/cm is among the lowest ever reported. The low-scale electric fields indicate likely polarization deterioration in the N-polarity structures. These conditions are favorable for bright PL up to room temperature in 8-9-nm-wide wells.

[关键词] MOLECULAR-BEAM EPITAXY;NONLINEAR MACROSCOPIC POLARIZATION;VAPOR-PHASE EPITAXY;WURTZITE GAN;ALGAN/GAN HETEROSTRUCTURES;RESOLVED PHOTOLUMINESCENCE;OPTICAL-PROPERTIES;WIDTH DEPENDENCE;ALN;BOUNDARIES