Structural and magnetic properties of an InGaAs/Fe$_3$Si superlattice in cylindrical geometry

Magnetic Properties of Short Period InGaMnAs/InGaAs Superlattices

We have observed a paramagnetic-to-ferromagnetic phase transition in short period InGaMnAs/InGaAs superlattices. The thicknesses of magnetic InGaMnAs layers in the structures studied was chosen to be 4 or 8 molecular layers (12 Åor 24 Å). The nonmagnetic InGaAs spacer layers are 12 Åthick. The In content of InGaMnAs and InGaAs layers was chosen in such a way that magnetic layers were: deep potential wells, high potential barriers or shallow potential wells. For superlattices with 8 monolayer thick InGaMnAs magnetic layers and 4 monolayer thick InGaAs nonmagnetic spacers the temperatures of par…

Demonstration of electron filtering to increase the Seebeck coefficient in ErAs:InGaAs/InGaAlAs superlattices

In this letter, we explore electron filtering as a technique to increase Seebeck coefficient and the thermoelectric power factor of heterostructured materials over that of the bulk. We present a theoretical model in which Seebeck coefficient and the power factor can be increased in an InGaAs based composite material. Experimental measurements of the cross-plane Seebeck coefficient are presented and confirm the importance of the electron filtering technique to decouple the electrical conductivity and Seebeck coefficient to increase the thermoelectric power factor.

Strain-induced InGaAs/InAlAs superlattices for terahertz radiation

We study the influence of residual strain in InGaAs/InAlAs superlattice (SL) on the ultrafast photocarrier dynamics under femtosecond laser excitation. We propose and fabricate a novel-designed strained InGaAs/InAlAs SL which allows us to obtain an ultrashort photocarrier relaxation time of $τ\sim$ 1.5 ps without Be-doping of the InGaAs photoconductor. We assume two dominant mechanisms to be responsible for a sharp reduction of $τ$: photocarriers trapping by defect levels in InAlAs barriers and increased photocarriers scattering at InGaAs/InAlAs interface roughness due to residual strain in th…

InGaAs/GaAs/alkanethiolate radial superlattices: Experimental

A radial InGaAs/GaAs/1-hexadecanethiol superlattice is fabricated by the roll-up of a strained InGaAs/GaAs bilayer passivated with a molecular self-assembled monolayer. Our technique allows the formation of multi-period inorganic/organic hybrid heterostructures. This paper contains the detailed experimental description of how to fabricate these structures.

Magnetic properties of GaMnAs single layers and GaInMnAs superlattices investigated at low temperature and high magnetic field

Magnetotransport properties of GaMnAs single layers and InGaMnAs/InGaAs superlattice structures were investigated at temperatures from 4 K to 300 K and magnetic fields up to 23 T to study the influence of carriers confinement through different structures. Both single layers and superlattice structures show paramagnetic-to-ferromagnetic phase transition. In GaMnAs/InGaAs superlattice beside the Curie temperature (Tc ~ 40 K), a new phase transition is observed close to 13 K.

应变平衡低温生长铍掺杂InGaAs/InAlAs超晶格用于1550 nm激光激发下的高性能太赫兹光电导体

Strain-Balanced Low-Temperature-Grown Beryllium-Doped InGaAs/InAlAs Superlattices for High-Performance Terahertz Photoconductors under 1550 nm Laser Excitation

本研究通过分子束外延制备了低温生长铍掺杂InGaAs/InAlAs应变平衡超晶格，发现其具有亚皮秒载流子寿命、增强迁移率和1550 nm吸收系数，为电信波长宽带太赫兹光电导探测器提供了高性能材料平台。