The impact of AsH3 overflow time and indium composition on the formation of self-assembled InxGa1 − xAs quantum dots studied by atomic force microscopy

Abstract

The outbreak of the disease and infection in the hospital environment and medical equipment is one of the concerns of modern life. One of the effective ways for preventing and reducing the complications of infections is modification of the surface. Here, the handmade atmospheric plasma spray system is used for accumulating copper as an antibacterial agent on the 316L stainless steel substrate, which applies to hospital environment and medical equipment. As a durable coating with proper adhesion is needed on the substrate, the effect of stand-off distance (SOD) which is an important parameter of the spray on the microstructure, the hardness and adhesion of the copper coating on the 316L stainless steel were investigated. The structure and phase composition of copper depositions were investigated using scanning electron microscopy and X-ray diffraction. The adhesion and hardness of depositions are evidenced using the cross cut tester and Vickers hardness tester, respectively. The findings confirm that the voids in the coatings increase with increasing SOD, which leads to decreasing the hardness of coatings and also the adhesion strength between depositions and substrate. In addition, by increasing the SOD, the oxygen content and the size of grains in the lamellae (fine structure) of coatings also increase.

Impact of gain compression factor on modulation characteristics of InGaAs/GaAs self-assembled quantum dot lasers

“…The 1.3 lm emission self-assembled InGaAs/ GaAs dots were first formed in 1994 by the alternate supply of Group-III and IV source materials with the quite low growth rate in metal-organic vapor phase epitaxy [9]. Some properties of self assembled quantum dot lasers (SAQDL) have been studied in [9][10][11]. Simulation of quantum dot lasers with two lasing states for InGaAs/GaAs quantum dot lasers emitting in 1.3 lm wavelength is also presented in [12][13][14].…”

On the electronic states in lens-shaped quantum dots

“…The confinement of electrons in all three directions of the space gives rise to a discrete energy spectrum ; and there is a deep analogy between such confined electrons and atoms . This offers considerable potential for applications in laser diodes and other novel optoelectronic devices, and for quantum–functional and memory devices . The performance of QD devices is affected by the size, shape, uniformity, composition, density, and structure of the dot .…”

Influence of Indium-Percentage Variation on Dynamical Characteristics of InxGa1-xAs/GaAs(001) Quantum Dot Lasers

“…It is shown that variation of materials percentages in epitaxial growth of QDs affects on both QD size and density, which directly changes the e-h recombination energies [19][20][21][22]. Some theoretical and experimental works elaborated to find the relationship between QD size and mismatch of the QD with the substrate [23,24]. Despite the relevance of quantum dot features and the result in lasing, there is in the literature a lack of simulations elaborating to find a way to connect the parameters of the structure of QD with the final laser properties.…”