P. Boonpeng

Fabrication of Self-Assembled InGaAs Squarelike Nanoholes on GaAs(001) by Droplet Epitaxy

The fabrication of self-assembled InGaAs squarelike nanoholes on GaAs(001) substrates grown by droplet epitaxy using molecular beam epitaxy was reported. The formation mechanism is explained by the As4 diffusion in droplets during the supply of As4 flux. The effects of substrate temperature (300–390 °C) during the InGa droplet deposition on their dimension and density were investigated. The surface morphology of InGaAs nanoholes as well as their depth profile was examined by atomic force microscopy (AFM). The square shape is oriented along [110] and [110] crystallographic directions with slightly different profiles due to anisotropy behavior. The size uniformity of the squarelike nanoholes is well controlled with less deviation at higher substrate temperatures.

GaP ring-like nanostructures on GaAs (100) with In0.15Ga0.85As compensation layers

We present the fabrication of GaP ring-like nanostructures on GaAs (100) substrates with inserted In0.15Ga0.85As compensation layers. The samples are grown by droplet epitaxy using solid-source molecular beam epitaxy. The dependency of nanostructural and optical properties of GaP nanostructures on In0.15Ga0.85As layer thickness is investigated by ex-situ atomic force microscope (AFM) and photoluminescence (PL). It is found that the characteristics of GaP ring-like structures on GaAs strongly depend on the In0.15Ga0.85As layer thickness.

In–Mole-Fraction and Thickness of Ultra-Thin InGaAs Insertion Layers Effects on the Structural and Optical Properties of InAs Quantum Dots

InAs quantum dots (QDs) have been grown by solid-source molecular beam epitaxy on different InxGa1-xAs (0 ≤ x ≤ 0.3) to investigate the effect of In-mole-fraction and thickness of InGaAs insertion layer (IL) on the structural and optical properties of the QDs. The density of QDs directly grown on GaAs is 1×1010 cm-2, and increase to 1.4-1.8×1010 cm-2 on InGaAs layers which depend on the In-mole-fraction and thickness of InGaAs layers. The effects of In-mole-fraction and thickness of InGaAs insertion layer on optical properties of the QDs are studied by photoluminescence (PL). The FWHM of PL spectrum corresponds to the size distribution of the QDs.