ABSTRACT
Figure 2 shows the contour plot of the piezoelectric potential, Vp, on the vertical cross section ( 1 0 Ϊ 0 ) of the In0.2Gao.sN pyramidal QD with the dot diameter = 86.4 A, height = 2 0 . 8 A, and φ = 30°. These diameter and height correspond to those of the smallest QD grown by MOCVD [2 ]. In the QD, Vp is maximum (« 0 . 1 eV) at the center of the bottom plane, and it is minimum (< —0 . 1 eV) at the QD top. The potential gradient in the vertical direction (the [0 0 0 1 ] direction) induces the vertical component of the internal piezoelectric field. This is analogous to the field in InGaN/GaN quantum wells. The lateral component of the field is much smaller. The piezoelectric field in the QD is largest at the center of the (0 0 0 1 ) plane at Z = 6.0 A; its value, -Fcente n is 1.64 MV/cm.
