Algorithm-Based Linearly Graded Compositions of GeSn on GaAs (001) via Molecular Beam Epitaxy.

The growth of high-composition GeSn films in the future will likely be guided by algorithms. In this study, we show how a logarithmic-based algorithm can be used to obtain high-quality GeSn compositions up to 16% on GaAs (001) substrates via molecular beam epitaxy. Herein, we use composition targeting and logarithmic Sn cell temperature control to achieve linearly graded pseudomorph GeSn compositions up to 10% before partial relaxation of the structure and a continued gradient up to 16% GeSn.

The growth of Ge and direct bandgap GeSn on GaAs (001) by molecular beam epitaxy.

Germanium tin (GeSn) is a tuneable narrow bandgap material, which has shown remarkable promise for the industry of near- and mid-infrared technologies for high efficiency photodetectors and laser devices. Its synthesis is challenged by the lattice mismatch between the GeSn alloy and the substrate on which it is grown, sensitively affecting its crystalline and optical qualities. In this article, we investigate the growth of Ge and GeSn on GaAs (001) substrates using two different buffer layers consisting of Ge/GaAs and Ge/AlAs molecular beam epitaxy.

Coherent-interface-induced strain in large lattice-mismatched materials: A new approach for modeling Raman shift.

Unlabelled: Strain engineering as one of the most powerful techniques for tuning optical and electronic properties of Ill-nitrides requires reliable methods for strain investigation. In this work, we reveal, that the linear model based on the experimental data limited to within a small range of biaxial strains (< 0.2%), which is widely used for the non-destructive Raman study of strain with nanometer-scale spatial resolution is not valid for the binary wurtzite-structure group-III nitrides GaN and AlN.

THERAPEUTIC APPROACHES TO THE CORRECTION OF COGNITIVE IMPAIRMENT IN PATIENTS WITH HYPERTENSION AND TYPE 2 DIABETES.

Objective: The aim: Was to improve the effectiveness of the treatment of cognitive impairment in patients with hypertension and type 2 diabetes.

Patients And Methods: Materials and methods: 56 patients (11 women and 45 men, average age 61.7 ± 4.

Impact of defects on photoexcited carrier relaxation dynamics in GeSn thin films.

We report the results of a study that was conducted to investigate the recombination paths of photoexcited charge carriers in GeSn thin films. The charge carrier lifetime was predicted as a function of temperature from a description of photoconductivity transients, assuming co-influence of Shockley-Read-Hall and radiative carrier recombination paths. We identify that dislocations are the source of a band of electronic states with the highest occupied state at E + (85÷90) meV that acts as Shockley-Read-Hall centers determining the charge carrier lifetime.