Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Interfaces-engineered M-structure for infrared detectors

Marchewka Michał, Jarosz Dawid, Ruszała Marta, Juś Anna, Krzemiński Piotr, Bobko Ewa, Trzyna-Sowa Małgorzata, Wojnarowska-Nowak Renata, Śliż Paweł, Rygała Michał, Motyka Marcin

Opto-Electronics Review

2024

Vol. 32, No. 2

art. no. e150183

In this paper, the authors report strain-balanced M-structures InAs/GaSb/AlSb/GaSb superlattice growth on GaSb substrates using two kinds of interfaces (IFs): GaAs-like IFs and InSb-like IFs. The in-plane compressive strain of 60-period and 100-period InAsm/GaSb/AlSbn/GaSb with different InAs (m) and AlSb (n) monolayers are investigated. The M-structures InAs/GaSb/AlSb/GaSb represent type II superlattices (T2SL) and at present are under intensive investigation. Many authors showtheoretical and experimental results that such structures can be used as a barrier material for a T2SL InAs/GaSb absorber tuned for long-wave infrared detectors (8 μm–14 μm). Beside that, M-structure can also be used as an active material for short-wave infrared detectors to replace InAs/GaSb which, for this region of infrared, are a big challenge from the point of view of balancing compression stress. The study of InAs/GaSb/AlSb/GaSb superlattice with the minimal strain for GaSb substrate can be obtained by a special procedure of molecular beam epitaxy growth through special shutters sequence to form both IFs. The authors were able to achieve smaller minimal mismatches of the lattice constants compared to literature. The high-resolution X-ray diffraction measurements prove that two types of IFs are proper for balancing the strain in such structures. Additionally, the results of Raman spectroscopy, surface analyses of atomic force microscopy, and differential interference contrast microscopy are also presented. The numerical calculations presented in this paper prove that the presence of IFs significantly changes the energy gap in the case of the investigated M-structures. The theoretical results obtained for one of the investigated structures, for a specially designed structure reveal an extra energy level inside the energy gap. Moreover, photoluminescence results obtained for this structure prove the good quality of the synthesized M-structures, as well as are in a good agreement with theoretical calculations.

Magnetotransport measurements as a tool for searching 3D topological insulators

Śliż Paweł, Sankowska Iwona, Bobko Ewa, Szeregij Eugeniusz, Grendysa Jakub, Tomaka Grzegorz, Żak Dariusz, Płoch Dariusz, Jasik Agata

Metrology and Measurement Systems

2021

Vol. 28, nr 4

725--734

The paper covers some measurement aspects of transport of electrons through metals and semiconductors in magnetic field - magnetotransport - allowing for the determination of electrical parameters characteristic of three-dimensional (3D) topological insulators (TI) (i.e. those that behave like an insulator inside their volume and have a conductive layer on their surface). A characteristic feature of the 3D TI is also a lack of differences between the chemical composition of the conductive surface and the interior of the material tested and the fact that the electron states for its surface conductivity are topologically protected. In particular, the methods of generating strong magnetic fields, obtaining low temperatures, creating electrical contacts with appropriate geometry were presented, and the measurement methods were reviewed. In addition, the results of magnetotransport measurements obtained for two volumetric samples based on the HgCdTe compound grown with the molecular beam epitaxy method are presented.