{"title":"Why is the band gap of GaP indirect while that of GaAs and GaN are direct?","authors":"Jinhai Huang, Wei Yang, Zihui Chen, Shengxin Yang, Kan-Hao Xue, Xiangshui Miao","doi":"10.1002/pssr.202300489","DOIUrl":"https://doi.org/10.1002/pssr.202300489","url":null,"abstract":"Many III-V semiconductors possess direct band gaps and are thus widely applied in optoelectronics. Although GaN (either in wurtzite phase or zinc blende phase), GaAs and GaSb are well-known direct gap semiconductors, GaP exhibits an indirect band gap nevertheless. This seems mysterious when considering that, P is between N and As among Group-VA elements and GaN has a direct gap even in the zinc blende structure. In this work, we analyze the generic rule of energy gaps in GaN, GaP and GaAs of the zinc blende phase, and study the trends of gap variation concerning the lattice constant and anion electronegativity. It is demonstrated that a compressed compound among the zinc blende III-V semiconductors is more likely to show an indirect band gap, while a tensed compound tends to possess a direct band gap. While GaP actually manifests a normal behavior, the reason why GaN surprisingly has a direct gap is analyzed through examining and perturbing its valence band as well as conduction band. It turns out that the conduction band electron shows a non-negligible probability to emerge near the N cores. The attractive nucleus potential pulls down the conduction band more strongly at Γ, which is in principle further supported through an analysis of the Kronig-Penney model. The difference between GaP and GaN in this respect is also analyzed in detail.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140075324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. N. Nair, I. Palacio, Y. Ohtsubo, A. Taleb-Ibrahimi, E.G. Michel, A. Mascaraque, A. Tejeda
{"title":"Electronic Structure Evolution in the Temperature Range of Metal Insulator Transitions on Sn/Ge(111)","authors":"M. N. Nair, I. Palacio, Y. Ohtsubo, A. Taleb-Ibrahimi, E.G. Michel, A. Mascaraque, A. Tejeda","doi":"10.1002/pssr.202400041","DOIUrl":"https://doi.org/10.1002/pssr.202400041","url":null,"abstract":"One third of monolayer of Sn adatoms on a Ge (111) substrate forms a two-dimensional triangular lattice with one unpaired electron per site. The system presents a metal-insulator transition when decreasing the temperature and it is known to exhibit strong electron-phonon coupling at 120-150 K. Here, we report a study of the electronic band structure for α-Sn/Ge(111) between 150 K and 5 K. We present both the experimental Fermi surfaces and the energy dispersions along high symmetry directions as a function of the temperature. At 5 K it is observed a weakly or low- dispersing spectral feature exhibiting an extended gap in the reciprocal space. This feature is derived from the topmost occupied band, which is metallic at high temperature and which develops a kink associated to strong electron-phonon coupling. The spectral evolution is partially explained with an increase of the electron-phonon coupling when decreasing the temperature. The increase of the electron-phonon coupling at low temperatures gives light into the new physics of this 2D system. The bandwidth is progressively reduced when reducing the temperature, enhancing the electronic correlation effects and triggering the Mott transition.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140075949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thomas Fernandes, Michael Texier, Philipp Hans, Cristian Mocuta, Solène Comby-Dassonneville, Gabriele Navarro, Simon Jeannot, Thomas W. Cornelius, Madeleine Han, Jaime Segura Ruiz, Martin Rosenthal, Yannick le Friec, Roberto Simola, Olivier Thomas
{"title":"Investigation of Phase Segregation Dynamics in Ge-rich GST Thin Films by In-situ X-ray Fluorescence Mapping","authors":"Thomas Fernandes, Michael Texier, Philipp Hans, Cristian Mocuta, Solène Comby-Dassonneville, Gabriele Navarro, Simon Jeannot, Thomas W. Cornelius, Madeleine Han, Jaime Segura Ruiz, Martin Rosenthal, Yannick le Friec, Roberto Simola, Olivier Thomas","doi":"10.1002/pssr.202300408","DOIUrl":"https://doi.org/10.1002/pssr.202300408","url":null,"abstract":"Ge-rich Ge-Sb-Te alloy is a good candidate for future automotive applications due to its high crystallisation temperature, which allows good data retention at elevated temperatures. Crystallization in this material is governed by elemental segregation which is key to thermal stability and device performance. In this work elemental (Ge, Sb, Te) segregation is studied <i>in situ</i> during thermal annealing of Ge-rich Ge-Sb-Te thin films using X-ray fluorescence microscopy at ID16B beamline of ESRF with a beam size of 50 nm. Spatially resolved maps of Ge, Te and Sb fluorescence yield are monitored and statistically analysed as function of temperature/time. In all investigated samples Sb appears to segregate much less than Te and Ge, indicating a lower mobility of this element. <i>In situ</i> fluorescence mapping of samples doped with different amounts of carbon by ion implantation shows that carbon delays Ge and Te segregation to higher temperatures. Comparison with crystallization kinetics monitored by X-ray diffraction shows a good correlation between the occurrence of spatially resolved chemical inhomogeneities and the appearance of crystallised phases.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140076151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An ultralow concentration of Cr2O3 dopants driven lower temperature sintering ZnO-based varistor ceramics","authors":"Yadong Cheng, Liaoying Zheng, Huarong Zeng, Tian Tian, Xue Shi, Zhenyong Man, Xuezheng Ruan, Guorong Li, Min Zhu","doi":"10.1002/pssr.202400030","DOIUrl":"https://doi.org/10.1002/pssr.202400030","url":null,"abstract":"Low working voltage driven ZnO-based varistor ceramics play an important role in the multilayer chip varistors, which require a low sintering temperature of ZnO varistor for its low energy consumption. Herein a remarkable reduction of the sintering temperature from the usual 1100°C-1300°C to 950°C was successfully achieved in the ZnO ceramics via a certain 0.05 mole percent of Cr<sub>2</sub>O<sub>3</sub> dopants. The underlying mechanism was found to be involved with the formation of basal-plane inversion boundaries between the ZnO grains, which can promote the rapid grain growth within the ceramics. Furthermore, the ZnO varistors with 0.05 mol% Cr<sub>2</sub>O<sub>3</sub> dopant exhibited excellent performance. A low breakdown voltage of 416 V/mm, a high nonlinear coefficient of 39, and a low leakage current of 3.4 μA were obtained simultaneously. This work presents an effective and promising approach for the cost-efficient preparation of high-performance ZnO-based varistors, which has particular significance for the application of multilayer chip varistors with low working voltage.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140076055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Carrier transport properties of the orthorhombic phase boron nitride nanoribbons and rectifying device design","authors":"Jun Zhao, Can Yao, Yunxi Qi, Hui Zeng","doi":"10.1002/pssr.202300498","DOIUrl":"https://doi.org/10.1002/pssr.202300498","url":null,"abstract":"Using density functional theory combined with non‐equilibrium Green’s function, we investigate the electronic structures and carrier transport properties of the orthorhombic phase boron nitride nanoribbons (BNNRs) with different edges and different widths. The calculated results show that both armchair‐ and zigzag‐edged BNNRs are direct bandgap semiconductors. The quantum confinement gives rise to a distinct bandgap for the one‐dimensional (1D) BNNRs, and the edged atoms play an important role on their electronic structures. The bandgaps of the armchair‐edged BNNRs approach 0.5∽0.8 eV when their widths are sufficiently large. However, the electronic structures of the zigzag‐edged BNNRs exhibit more variations dependent on their edged atoms. The <jats:italic>J‐V</jats:italic> characteristics of the BNNRs reveal that the zigzag‐edged BNNRs have superior <jats:italic>J‐V</jats:italic> performance to that of the armchair‐edged counterparts. Eventually, we propose a computational nanodevice design to achieve rectifying behavior by constructing an in‐plane heterojunction based on the BNNRs without any doping, and the left‐ and right‐electrode is formed by differnetly edged atoms and a small strain is performed on the left‐electrode. The rectification ratio of about 77.36 is realized. Our findings provide comprehensive understandings of the orthorhombic boron nitride monolayer, which could be helpful to its potential application for nanoelectronics.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140055316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexey Efimov, Anton Patarashvili, Dmitry Maslennikov, Vladislav Davydov, Denis Kornyushin, Mohammad Reza Ghorbani Fard, Dmitry Labutov, Vitaly Torgunakov, Margarita Zebreva, Victor Ivanov
{"title":"High‐resolution patterning of conductive microstructures by electrostatic deposition of aerosol Au nanoparticles through the dielectric mask","authors":"Alexey Efimov, Anton Patarashvili, Dmitry Maslennikov, Vladislav Davydov, Denis Kornyushin, Mohammad Reza Ghorbani Fard, Dmitry Labutov, Vitaly Torgunakov, Margarita Zebreva, Victor Ivanov","doi":"10.1002/pssr.202300492","DOIUrl":"https://doi.org/10.1002/pssr.202300492","url":null,"abstract":"A new approach of electrostatically focusing nanoparticles through an electrical tape mask to form narrow <10 <jats:italic>μm</jats:italic> and conductive microstructures is developed and investigated in this work. The presented approach is similar to deposition of material through a stencil and allows one to obtain lines 15 times smaller than the width of the gap in the mask. It is proposed to use ordinary PVC electrical tape as a mask instead of expensive photo or electronic resists. The work investigated the influence of a mask thickness (height) of 60–180 <jats:italic>μm</jats:italic>, a gap width of 120–380 <jats:italic>μm</jats:italic>, a substrate potential of 0.1–5 kV, and a deposition time of 10 and 120 min on the geometry and electrical properties of the lines. The substrate material was Si, and charged Au nanoparticles 60 nm in size synthesized by spark discharge were the building blocks of microstructures. Numerical modeling of the process of focusing nanoparticles in COMSOL qualitatively confirmed the found experimental dependencies. The electrical resistivity of the sintered lines is 6.34 times higher than that of bulk gold. The developed approach makes it possible to obtain high‐aspect microstructures, supports operation at atmospheric pressure, and is flexibly controlled in terms of the choice of materials.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140036355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. N. Apostolova, A. T. Apostolov, J. M. Wesselinowa
{"title":"Electric, dielectric and phonon properties of Cu2OCl2$left(text{Cu}right)_{2} left(text{OCl}right)_{2}$","authors":"I. N. Apostolova, A. T. Apostolov, J. M. Wesselinowa","doi":"10.1002/pssr.202400005","DOIUrl":"https://doi.org/10.1002/pssr.202400005","url":null,"abstract":"Investigating the multiferroic properties of we analyze their temperature and magnetic field dependencies around the magnetic and ferroelectric phase transition temperatures and using a microscopic model and Green’s function technique. Near the Neel temperature we observe a kink in the specific heat and also in the phonon energy and damping due to strong anharmonic spin‐phonon interaction. The kink in disappears with increasing magnetic field <jats:italic>h</jats:italic>. The polarization shows also a small anomaly at and decreases with increasing magnetic field <jats:italic>h</jats:italic>. This behavior strongly suggests that exhibits multiferroic characteristics. A kink at can be seen in the real part of the dielectric constant , too. It should be noted that demonstrates a significant increase with increasing field strength <jats:italic>h</jats:italic> below , which is a pronounced magneto‐dielectric effect. Our findings qualitatively agree with the experimental data.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140036141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Deep‐ultraviolet luminescence properties of AlN","authors":"Ryota Ishii, Akira Yoshikawa, Mitsuru Funato, Yoichi Kawakami","doi":"10.1002/pssr.202400017","DOIUrl":"https://doi.org/10.1002/pssr.202400017","url":null,"abstract":"High‐resolution, low‐excitation photoluminescence (PL) spectroscopy was performed for unintentionally doped, silicon‐doped, and magnesium‐doped homoepitaxial aluminum nitride (AlN) films, using a wavelength‐tunable high‐repetition‐rate laser. The wavelength‐tunable laser was used to distinguish between the luminescence and scattering signals from AlN. Providing the high‐resolution, low‐excitation PL spectra, the current understanding of the deep‐ultraviolet luminescence properties of AlN is reviewed and potential assignments for the unknown luminescence lines and bands are discussed. Although previous studies have led to a consensus on the origins of some emission peaks and bands such as the neutral silicon donor‐bound exciton transition and free exciton transitions involving longitudinal optical phonons, it is shown that many of the emission peaks are still unidentified. The origins of all the emission peaks should be elucidated to enable control of the electronic and optoelectronic properties of AlN.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140055351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Deep-Red (Sr,Ba)Lu2O4: Eu2+ Phosphor for Full-Spectrum Lighting","authors":"Shaoxiong Wang, Fengluan You, Shaojun Wang, Tao Pang, Lingwei Zeng, Shisheng Lin, Yuanhui Zheng, Yongzheng Fang, Daqin Chen","doi":"10.1002/pssr.202400061","DOIUrl":"https://doi.org/10.1002/pssr.202400061","url":null,"abstract":"Developing violet-light-excitable deep-red (650∽660 nm) Eu<sup>2+</sup> activated phosphor is essential for full-spectrum lighting. However, the related phosphors with facile synthesis, excellent optical performance and superior thermal stability are scarce. Herein, we report a new class of (Sr,Ba)Lu<sub>2</sub>O<sub>4</sub>: Eu<sup>2+</sup> deep-red phosphor (660 nm) excitable by violet light via Ba<sup>2+</sup>-induced local structure engineering. Impressively, tunable emission from 615 nm to 682 nm, accompanied with significant improvement of thermal stability (81%@423K), is achieved by partially substituting Sr<sup>2+</sup> by Ba<sup>2+</sup> in SrLu<sub>2</sub>O<sub>4</sub>: Eu<sup>2+</sup>. Crystal-field analysis, density functional theory (DFT) calculations and thermoluminescence (TL) spectra confirm that the strong distortion and enhanced covalency of [EuO<sub>6</sub>] octahedron are responsible for spectral tunability and the formation of shallow trapping states is beneficial for electron compensation to inhibit thermal quenching in the Sr<sub>0.85</sub>Ba<sub>0.15</sub>Lu<sub>2</sub>O<sub>4</sub>: Eu<sup>2+</sup> phosphor. Finally, a white light-emitting diode (wLED) prototype fabricated by coupling the Sr<sub>0.85</sub>Ba<sub>0.15</sub>Lu<sub>2</sub>O<sub>4</sub>: Eu<sup>2+</sup> deep-red phosphor and commercial blue/green phosphors with violet chip can yield sunlight-like white light with an ultra-high color rendering index (CRI: R<sub>a</sub>=95.2, R<sub>9</sub>=97.0) and an appropriate correlated color temperature (CCT) of 4121 K, verifying its significant application potential in full-spectrum solid-state lighting.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140025442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eugène Bertin, Éric Gautron, Nicolas Barreau, Charles Cornet, Ludovic Arzel, Leo Choubrac, Antoine Létoublon, Sylvie Harel, Rozenn Bernard, Maud Jullien, Rohel Tony, Lionel Assmann, Olivier Durand
{"title":"Evidence of cationic antiphase disorder in epitaxial Cu(In,Ga)S2 grown on GaP/Si(001)","authors":"Eugène Bertin, Éric Gautron, Nicolas Barreau, Charles Cornet, Ludovic Arzel, Leo Choubrac, Antoine Létoublon, Sylvie Harel, Rozenn Bernard, Maud Jullien, Rohel Tony, Lionel Assmann, Olivier Durand","doi":"10.1002/pssr.202300485","DOIUrl":"https://doi.org/10.1002/pssr.202300485","url":null,"abstract":"We present a transmission electron microscopy study of epitaxial Cu(In,Ga)S<jats:sub>2</jats:sub> (CIGS) films co‐evaporated on GaP/Si(001), in either Cu‐rich or Cu‐poor conditions. We first unveil the spatial distribution and the orientation of the different phases by means of electron diffraction. From atomically resolved imaging of the CIGS film’s atomic structure, we conclude that different chalcopyrite domains, sharing cation antiphase symmetries of the cation sublattice, coexist in the films. We conceptualize at least three types of cation antiphase boundaries (CAPBs), which does or does not lead to a violation of the octet rule, depending on the propagation direction. Even though we observe that epitaxial CIGS is highly prone to cation antiphase disorder, we find that the growth of CIGS in Cu‐rich conditions leads to a lower density of CAPBs, as compared to Cu‐poor growth conditions. This opens the question of the influence of CAPBs on CIGS electronic properties.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140019754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}