Electronic Properties Of InAs Research Articles

Effect of Vacancy Concentration on Elastic and Electronic Properties of InAs and GaAs: Towards Defected Structures of Nanoobjects.

This paper pertains to elastic properties of InAs and GaAs semiconducting crystals containing various amounts of vacancies--the relevant issue in the case of nanostructured electronic materials. The linear relationship between elastic constants and point defects concentration deduced from our classical molecular dynamic and ab initio calculations, confirms that an increasing vacancy content results in a decrease of pertinent elastic parameters, namely the crystal elastic stiffness-tensor components, the effect called herein "the softening of material" for simplicity. The pseudo-potential-based approach provides us results compatible with the available experimental data, while the alternatively used empirical potentials failed to account for different kind of vacancies on the elastic properties of semiconductors. Our results provide an expanded insight into the problems of modeling of the properties of the defected InAs and GaAs crystal structures. This issue is of interest to nanoelectronics and production of nanomaterials currently.

Carrier relaxation dynamics in InAs∕InP quantum dots

The electronic properties of InAs∕InP(113)B double-cap quantum dots (QDs) emitting around 1.55μm are investigated. The carrier dynamics in QDs is studied by nonresonant time-resolved photoluminescence experiments. This analysis reveals the electronic structure of the QDs and the transient filling of the confined levels. Under low excitation densities, the spontaneous exciton lifetime is estimated and compared to time-resolved experiments. Under high excitation density, a direct Auger recombination effect is identified. The temperature analysis enables us to distinguish Auger and phonon-assisted relaxation processes.

Magnetophotoluminescence study of the influence of substrate orientation and growth interruption on the electronic properties of InAs∕GaAs quantum dots

We have used photoluminescence in pulsed (⩽50T) and dc (⩽12T) magnetic fields to investigate the influence of substrate orientation and growth interruption (GI) on the electronic properties of InAs∕GaAs quantum dots, grown by molecular beam epitaxy at 480°C. Dot formation is very efficient on the (100) substrate: electronic confinement is already strong without GI and no significant change in confinement is observed with GI. On the contrary, for the (311)B substrate strong confinement of the charges only occurs after a GI is introduced. When longer GIs are applied the dots become higher.

Ion beam etching induced structural and electronic modification of InAs and InSb surfaces studied by Raman spectroscopy

The modification of the structural and electronic properties of InAs and InSb surfaces induced by low-energy N2 and Ar ion beam etching (IBE) were investigated as a function ion energy (⩽500 eV) using Raman spectroscopy. A drastic enhancement of the electron concentration in the near surface region of both materials independent of the ion energy and the process gas was observed. From Raman measurements in different polarization configurations it can be concluded that the electron accumulation observed after IBE is inherently related to the process-induced structural defects. The degree of structural damage and the carrier concentration in the near surface region increase for higher ion energies. By controlled, subsequent removal of the damaged surface layer using wet etching, the depth profile of the structural and electronic damage in InAs was determined. This procedure reveals that the structural and electronic damage extends about 100 nm into the material. Nevertheless, it can be recognized that the utilization of N2 as the etching gas is associated with a lower degree of damage and also a lower electron accumulation at the surface of both InAs and InSb.