Efficient Emission in the Telecom Range from Quantum Dots Embedded in Photonic Structures Fabricated by Focused Ion Beam Milling

Abstract

IV-VI semiconductors possess intriguing multifunctional characteristics, such as topological surface states, ferroelectricity at room temperature, and giant Rashba spin-splitting, giving them the potential for next-generation spintronic applications. In this work, we are presenting the epitaxially grown layers α-GeTe and SnTe, their structural and high field magnetotransport results. The crystal structure of α-GeTe preserves the rhombohedral symmetry (R3m) below T ≈ 720 K manifesting ferroelectric polarization, whereas SnTe holds the cubic symmetry (F m-3m) above T ≈ 80 K. The results of the variable temperature in the range 4.3 ≤ T ≤ 300 K show a weakly dependent charge concentration, i.e., p(T ) = 0.1 × 10 21 cm −3 for SnTe and p(T ) = 0.7 × 10 21 cm −3 for α-GeTe layers. Likewise, the hole mobility µ h (T ) remains almost constant in the range 4.3 ≤ T ≤ 15 K and changes to a metallic-like behavior when T ≥ 15 K. Furthermore, the high field magnetoresistance ρxx(B) graphs of SnTe layers, measured between −13 ≤ B ≤ 13 T, demonstrate a prominent weak anti-localization effect below T = 3 K and when |B| ≤ 0.3 T. However, the weak anti-localization effect disappears at T = 4.2 K for both the α-GeTe and SnTe epitaxial layers. Similarly, the ρxx(B) graphs of α-GeTe show a small effect only at the lowest temperature measured T = 1.6 K. The calculated prefactor value α = −14, obtained by fitting the ∆σxx(B) graphs with the Hikami-Larkin-Nagaoka model, indicates the bulk transport system in SnTe. topics: IV-VI semiconductors (SCs), weak anti-localization effect, bulk conductivity

Nanotubular Arrayed LIPSS Achieved with Femtosecond Bessel Beam on Silver Surface for SERS-Based Multiple Explosive Sensing

“…The evergreen world of nanostructured surfaces, which ascended on the shoulders of ultrashort laser−matter irradiation, is of high interest for various scientific, biomedical, and industrial applications. 1 Numerous techniques are available for creating nanostructured surfaces, encompassing sputtering, chemical 2 and plasma etching, 3 chemical vapor deposition, 4,5 self-assembly, nanoimprint, 6 optical, electron beam, and physical lithography, 7,8 and more. 9 However, ultrashort laser irradiation has emerged as a robust and efficient alternative for producing diverse nanotextured surfaces, notably laser-induced periodic surface structures (LIPSS).…”

“…The evergreen world of nanostructured surfaces, which ascended on the shoulders of ultrashort laser–matter irradiation, is of high interest for various scientific, biomedical, and industrial applications . Numerous techniques are available for creating nanostructured surfaces, encompassing sputtering, chemical and plasma etching, chemical vapor deposition, , self-assembly, nanoimprint, optical, electron beam, and physical lithography, , and more . However, ultrashort laser irradiation has emerged as a robust and efficient alternative for producing diverse nanotextured surfaces, notably laser-induced periodic surface structures (LIPSS). − LIPSS represents a captivating realm of research, presenting promising applications spanning hydrogen evolution, photochemical water splitting, , solar-thermal conversion, data storage, surface chemistry, photodetectors, and biomedical applications. − This burgeoning field of nanopatterning serves as the cornerstone of fields such as the semiconductor industry, microelectronics, and photocatalysis .…”