The strain field distributions have important impacts on mechanical stability,piezoelectric effect and photoelectric effect of quantum dots.Based on the finite element approach,and considering the wurtzite structure of InN and GaN,investigated are the strain field distributions of lens,flattened hexagonal pyramid and hexagonal pyramid-shaped quantum dots.The results show that the strain field distributions are focused in quantum dots and wetting layer,so it should be noticed that the wetting layer has an ef...