Optical anisotropy of cubic crystals, from bulk to quantum dots

Asymmetry of the Atomic Core Structure of Dissociated a‐Screw Dislocation in GaN Probed by Polarization Optical Spectroscopy

“…Under application of an external electric field along the growth direction, the free carrier wave function shifts away from one interface toward the opposite one, removing the equivalence of the physical properties of the interfaces. A strong field‐induced polarization of the spatially indirect optical transition via the interfaces was observed experimentally in one of two orthogonal directions depending on the sign of the applied voltage to the structure . Similar effect was also observed in the ZnSe/BeTe structures at asymmetrical interfaces with the absence of electric field, providing possibility to define the orientation of chemical bonds from polarization sensitive measurements.…”

“…The second type of the optical anisotropy is in‐plane anisotropy in cubic crystals that was theoretically predicted by Krebs and Voisin and observed for spatially indirect optical transition at the interfaces of various QWs (for review, see Kochereshko et al). The reason for the anisotropy is the different orientations of chemical bonds at the opposite interfaces of QW grown in the [001] direction.…”

“…It was established that direct optical transitions confined within QW are not sensitive to the atomic structure at the interfaces and are polarization isotropic. In contrast, spatially indirect transitions through the QW interfaces exhibited strong polarization anisotropy caused by different orientations of chemical bond directions at opposite walls of QWs that appears or enhances in the presence of electric field (for review, see Kochereshko et al).…”

Unusual Polarization Dependence of Dislocation‐Related Luminescence in n‐GaN

“…It was established that direct optical transition confined within QW is not sensitive to the atomic structure at the interfaces and is polarization isotropic. In contrast to that, spatially indirect transitions through the QW interfaces exhibited strong polarization anisotropy caused by different orientations of chemical bond directions at opposite walls of QWs that appears or enhances in the presence of electric field (for review, see the study given by Kochereshko et al [12] ).…”

“…Polarization dependences of normalized intensities of DRL H and DRL L peaks are shown in Figure 3b. The direction [11][12][13][14][15][16][17][18][19][20] of the dislocation lines is marked with black vertical arrow near an angle of polarization of about 160 . From the graph in Figure 3b, one can see that the polarization direction for DRL L peak is shifted at an angle of about 40 relative to one of DRL H , or the dislocation line direction.…”