Abstract Analog switching in ferroelectric devices promises neuromorphic computing with the highest energy efficiency if limited device scalability can be overcome. To contribute to a solution, one reports on characteristics of sub‐5 nm thin Al 0.74 Sc 0.26 N films grown Pt/Ti/SiO 2 /Si and epitaxial Pt/GaN/sapphire templates by sputter‐deposition. In this context, study focuses following major achievements compared previously available wurtzite‐type ferroelectrics: 1) Record low voltages...

Abstract Wurtzite‐type Al 1− x Sc N solid solutions grown by metal organic chemical vapor deposition are for the first time confirmed to be ferroelectric. The film with 230 nm thickness and = 0.15 exhibits a coercive field of 5.5 MV cm −1 at measurement frequency 1.5 kHz. single crystal quality homogeneous composition X‐ray diffraction spectroscopic methods such as flight secondary ion mass spectrometry. Annular bright scanning transmission electron microscopy serves prove ferroelectric...

This work presents the first atomic scale evidence for ferroelectric polarization inversion on unit cell level in a wurtzite-type material based epitaxial Al0.75Sc0.25N thin films. The electric field induced formation of Al-polar domains originally N-polar film is unambiguously determined by resolution imaging using aberration-corrected scanning transmission electron microscopy (STEM). Anisotropic etching supports STEM results confirming complete and homogenous at surface switched regions...

Through its dependence on low symmetry crystal phases, ferroelectricity is inherently a property tied to the lower temperature ranges of phase diagram for given material. This paper presents conclusive evidence that in case ferroelectric Al1−xScxN, has be seen as purely relative term, since ferroelectric-to-paraelectric transition confirmed surpass 1100 °C and thus virtually any other thin film ferroelectric. We arrived at this conclusion through investigating structural stability 0.4–2 μm...

Abstract The recent emergence of wurtzite‐type nitride ferroelectrics such as Al 1‐ x Sc N has paved the way for introduction all‐epitaxial, all‐wurtzite‐type ferroelectric III‐N semiconductor heterostructures. This paper presents first in‐depth structural and electrical characterization an epitaxial heterostructure by investigating sputter deposited solid solutions with between 0.19 0.28 grown over doped n‐GaN. results detailed investigations on strain state initial unit‐cell polarity...

The discovery of ferroelectricity in aluminum scandium nitride (Al1-xScxN) opens technological perspectives for harsh environments and space-related memory applications, considering the high-temperature stability piezoelectricity nitride. ferroelectric material properties 100 nm-thick Al0.72Sc0.28N are studied up to 873 K, combining both electrical situ X-ray diffraction measurements as well transmission electron microscopy energy-dispersive spectroscopy. present work demonstrates that can...

Thickness scaling of ferroelectricity in AlScN is a determining factor for its potential application neuromorphic computing and memory devices. In this letter, we report on ultrathin (10 nm) Al0.72Sc0.28N films that are ferroelectrically switchable at room temperature. All-epitaxial Al0.72Sc0.28N/Pt heterostructures grown by magnetron sputtering onto GaN/sapphire substrates followed an situ Pt capping approach to avoid oxidation the film surface. Structural characterization X-ray diffraction...

Abstract This study examines systematic oxygen ( O )‐incorporation to reduce total leakage currents in sputtered wurtzite‐type ferroelectric Al 0.73 Sc 0.27 N thin films, along with its impact on the material structure and polarity of as‐grown films. The bulk was introduced through an external gas source during reactive sputter process. In comparison samples without doping, ‐doped films showed almost a fourfold reduction overall current near coercive field. addition, doping resulted...

Ferroelectric thin films of wurtzite-type aluminum scandium nitride (Al1−xScxN) are promising candidates for non-volatile memory applications and high-temperature sensors due to their outstanding functional thermal stability exceeding most other ferroelectric film materials. In this work, the expansion along with temperature its interrelated effects have been investigated Al1−xScxN on sapphire Al2O3(0001) Sc concentrations x (x = 0, 0.09, 0.23, 0.32, 0.40) using in situ X-ray diffraction...

AlxSc1–xN is a nitride-ferroelectric compatible with both CMOS and GaN technology. The origin of ferroelectricity in these ternary nitrides relies on the full inversion nitrogen atom positions, which significantly different structural mechanism than conventional perovskites. Therefore, its ferroelectric characteristics exhibit high remanent polarization tunable coercive field but suffer heavily from leakage currents during switching event. In this article, we studied epitaxially grown...

In this work, we present a method for growing highly c-axis oriented aluminum scandium nitride (AlScN) thin films on (100) silicon (Si), dioxide (SiO2) and epitaxial polysilicon (poly-Si) substrates using substrate independent approach. The presented offers great advantages in applications such as piezoelectric thin-film-based surface acoustic wave devices where metallic seed layer cannot be used. approach relies AlN to establish wurtzite nucleation the growth of w-AlScN films. Both AlScN...

Abstract The material design of functional “aero”‐networks offers a facile approach to optical, catalytical, or and electrochemical applications based on multiscale morphologies, high large reactive area, prominent diversity. Here in this paper, the synthesis structural characterization hybrid β‐Ga 2 O 3 /ZnGa 4 nanocomposite aero‐network are presented. networks studied with respect their micro‐ nanostructure by X‐ray diffraction (XRD) transmission electron microscopy (TEM) characterized for...

Analog switching in ferroelectric devices promises neuromorphic computing with highest energy efficiency, if limited device scalability can be overcome. To contribute to a solution, we report on the characteristics of sub-5 nm thin Al$_{0.74}$Sc$_{0.26}$N films grown Pt/Ti/SiO2/Si and epitaxial Pt/GaN/sapphire templates by sputter-deposition. In this context, focus following major achievements compared previously available wurtzite-type ferroelectrics: 1) Record low voltages down 1 V are...

Network Materials In article number 2207492, Niklas Wolff, Ion Tiginyanu, Lorenz Kienle, and co-workers report on the synthesis structural characterization of a hybrid wide-band-gap semiconductor nanocomposite network interconnected hollow microtubes composed β-Ga2O3/ZnGa2O4 phases using X-ray powder diffraction transmission electron microscopy. The aero-network morphology shows ZnGa2O4-dominated narrow band green light emission under UV excitation high initial electrochemical capacity...

This article examines systematic oxygen (O)-incorporation to reduce total leakage currents in sputtered wurtzite-type ferroelectric Al0.73Sc0.27N thin films, along with its impact on the material structure and polarity of as-grown films. The O bulk was introduced through an external gas source during reactive sputter process. In comparison samples without doping, O-doped films showed almost a fourfold reduction current near coercive field. addition, doping resulted steady-state by roughly...

Wurtzite-type Al$_{1-x}$Sc$_x$N solid solutions grown by metal organic chemical vapour deposition are for the first time confirmed to be ferroelectric. The film with 230 nm thickness and x = 0.15 exhibits a coercive field of 5.5 MV/cm at measurement frequency 1.5 kHz. Single crystal quality homogeneous composition was X-ray diffraction spectroscopic methods such as flight secondary ion mass spectrometry. Annular bright scanning transmission electron microscopy served proof ferroelectric...

This article presents, a photonic crystal fiber (PCF) with four layers hexagonal formation of air holes for sensing index refraction (RI). Numerical investigation is performed between the analyte detection ranges from 1.38 to 1.42 by using finite element method (FEM). Simulation this reveal maximum wavelength sensitivity (WS) 20,000 nm/RIU and amplitude (AS) 718 RIU <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> . The sensor resolution...

Thickness scaling of ferroelectricity in AlScN is a determining factor for its potential application neuromorphic computing and memory devices. In this letter, we report on ultrathin (10 nm) Al0.72Sc0.28N films that are ferroelectrically switchable at room temperature. All-epitaxial Al0.72Sc0.28N/Pt heterostructures grown by magnetron sputtering onto GaN/sapphire substrates followed an situ Pt capping approach to avoid oxidation the film surface. Structural characterization X-ray diffraction...

Through its dependence on low symmetry crystal phases, ferroelectricity is inherently a property tied to the lower temperature ranges of phase diagram for given material. This paper presents conclusive evidence that in case ferroelectric AlScN, has be seen as purely relative term, since ferroelectric-to-paraelectric transition confirmed surpass 1100{\deg}C and thus virtually any other thin film ferroelectric. We arrived at this conclusion through investigating structural stability 0.4 - 2...