The Strain Anaysis And Characteristic Study Of InN Quantum Dots

Firstly,we calculated the critical thickness of InN/GaN quantum dots.And based on the finite element approach, and considered the wurtzite structure of InN and GaN,we investigated the strain field distributions of lens,flattened hexagonal pyramid and hexagonal pyramid-shaped quantum dots that have the same aspect ratio. The results show that the strain field distributions are focused in quantum dots and wetting layer,and the wetting has an effect on electronic energy level in quantum dots.And we also discussed the energy of three kinds of quantum dots. the hexagonal pyramid-shaped quantum dots are steadiest.The results consistent with the theory and literature.Secondly,the most stable structure is hexagonal pyramid that receibed by calculation and experimentals,so we compared the strain field distribution of non-buried and buried hexagonal pyramid-shaped quantum dots that prapared by same conditions.And we also calculated the energy of two kinds of quantum dots.The covering layer brought a new strain,and make the conduction band moves to higher energy level.And it also increased the energy of quantum dots.Last,we detected three kinds of quantum dots that had different aspect ratio and density by X-ray double crystal diffraction,AFM and PL.And we also calculated the strain field distribution and energy that including the wettin layer of three kinds of quantum dots.The size of quantum dots is smaller,the strain relaxation is smaler,the light wavelength is shorter,and energy of quantum dots is lower.As the temperature decreasing,the light wavelength blue shift.The spectrum broadening has important relationship with the temperature.