The effect of InAlAs deposition thickness on the areal density

size

uniformity and spatial distribution of self-organized In

0.65

Al

0.35

As/Al

0.5

Ga

0.5

As quantum dots was studied

grown on(001)GaAs substrate by molecular-beam epitaxy(MBE).The progression of surface morphology of In

0.65

Al

0.35

As quantum dots is investigated in detail by atomic force microscopy(AFM).A high density

small size

red-emission self-organized In

0.65

Al

0.35

As quantum dots have been obtained.The self-organized In

0.65

Al

0.35

As quantum dots density and average size are found to increase with increasing the InAlAs deposition thickness.Moreover

the increase of dots density is slow

compared with the variance of InAs/GaAs quantum dots with InAs deposition thickness

this might be beneficial for the realization of low-threshold quantum dot lasers since both quantum confinement and gain region are increased.It was found that the surface diffusion of Al atoms is an important factor in determining the structural properties of In

0.65

Al

0.35

As quantum dots.We believe that the Al atom of the smaller surface migration range plays a large role in determining In

0.65

Al

0.35

As quantum dots nucleation sites.The low-temperature photoluminescence(PL)from the recombination of carriers in the buried In

0.65

Al

0.35

As/Al

0.5

Ga

0.5

As quantum dots is observed 1.701eV-energy position

its linewidth is determined principally by the lateral size of dots through investigating the distribution of dots size.