OAJ Materials and Devices http://caip.co-ac.com/index.php/materialsanddevices <p>Materials and Devices is an Open Access journal managed by academics, which publishes original, and peer-reviewed papers accessible only via internet, freely for all. Your published article can be freely downloaded, and self archiving of your paper is allowed and encouraged!</p> <p>The topics covered by the journal are wide, Materials and Devices aims at publishing papers on all aspects of studies on materials, and related devices. This includes solid state physics and chemistry, chemical physics, materials science, microelectronics, photonics,... and all types of materials.</p> <p>Papers on biomaterials, geomaterials, archeomaterials or on studies of ancient materials are also welcome. A particular attention is also paid on environmental studies related with materials and on materials relevant to environment preservation.</p> <p>Authors are also encouraged to submit papers on theoretical studies applied to materials, including pure mathematical approaches, physical approaches, models, numerical simulations, etc.</p> <p>We apply « the principles of transparency and best practice in scholarly publishing» as defined by the Committee on Publication Ethics (COPE).<br /><br />Materials and Devices is now indexed by the DOAJ and published articles receive a DOI. </p> <p>Articles are published under the responsability of authors, in particular concerning the respect of copyrights; we ask authors to consider this point very seriously because any figure (or table) already published (even by the author himself) in another journal is generally submitted to copyrights. In that case authors should ask for permission to reproduce the figure in his article.</p> <p>Another very important point is plagiarism. Authors should be careful not to plagiarize other works; we check articles for plagiarism, and authors who would submit a plagiarized article (or partially plagiarized) will be bannished from the journal.</p> <p>Readers are aware that the contents of published articles may involve hazardous experiments if reproduced; the reproduction of experimental procedures described in articles is under the responsability of readers and their own analysis of potential danger.</p> <p><strong>Downloads: <a href="http://co-ac.com/wp-content/uploads/2019/05/Flier-MatDev2019.pdf">Flier of the journal </a> Article templates:</strong> there is a special template for review articles, other types of articles may be edited with the general template. See the last issue of the journal to get the updated templates, containing also instructions for authors.</p> Collaborating Academics en-US OAJ Materials and Devices 2495-3911 <p><strong>Authors who publish with this journal agree to the following terms:</strong><br /><br /></p> <ol type="a"> <ol type="a"> <li>Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License ( <a href="http://creativecommons.org/licenses/by-nc-nd/4.0/" rel="license">Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licens</a>e) that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.</li> <li>To the extent transferable, copyright in and to the undersigned article is hereby assigned to Collaborating Academics and Open Access Journal Materials and Devices (ISSN: 2495-3911) for publication in the website of the journal and as part of a book (eventually a special volume) that could be produced in a printed and/or an electronic form.</li> <li>Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See <a style="background-color: #ffffff;" href="http://opcit.eprints.org/oacitation-biblio.html" target="_new">The Effect of Open Access</a>).</li> <li>Figures, tables, and other information present in articles published in the OAJ Materials and Devices may be reused without permission, provided the citation of original article is made in figure's or table's caption.</li> </ol> </ol> What is the weight: how and why it occurs for gaseous matter http://caip.co-ac.com/index.php/materialsanddevices/article/view/160 <p>A pure mechanical approach is proposed to gain a more penetrating insight into the physical meaning of the body’s weight, in deducing its notion just from the Newton’s equation for the body moving along the gravitational field. In that view, the body is weighty when its acceleration along the <em>g</em>-field is other than <em>g</em>. The approach was used for to account the occurrence of the gaseous matter weight that was regarded by us as some sort of <em>experimentum crucis</em> capable of estimating its validity. According to the results obtained, the body’s weight is a physical reality fundamentally different from the force of gravity, and represents the inevitable factor assuring the fulfilment of the momentum conservation law in the body – Earth system.</p> Mikhail Smirnov Andrey Mirgorodsky Copyright (c) 2023 Mikhail Smirnov, Andrey Mirgorodsky https://creativecommons.org/licenses/by-nc-nd/4.0 2024-02-05 2024-02-05 7 Insight into negative trions binding energy behavior inside type-I and reversed type-I core/shell quantum dots: A variational analysis http://caip.co-ac.com/index.php/materialsanddevices/article/view/155 <p><span class="fontstyle0">Many body interactions between single particles inside low-dimensional semiconducting materials play a critical role in their optical characteristics. Within this context, tuning trionic and excitonic binding energy enables tailoring of the optical band gap of a given material. In this paper, we theoretically investigated the binding energy (</span><span class="fontstyle2">E</span><span class="fontstyle3">b</span><span class="fontstyle0">) of negatively charged excitons inside GaN/AlN type-I, and AlN/GaN inverted type-I core/shell quantum dots. Firstly, we started our study by examining the variation in the energy of electrons (holes) according to the change in the internal and external radii { as a means to obtain an insight into the energetic behavior of non-correlated single particles inside the two understudied nanosystems. The feature of the radial probability density distribution of confined single particles and negative trions is also discussed. Afterwards, we examined the impact of the heteronanodot spatial parameters (core radius and shell thickness) on the binding energy of confined trions. A comparison between the </span><span class="fontstyle2">E</span><span class="fontstyle3">b </span><span class="fontstyle0">behavior of negative trions inside core/shell type-I, and reversed type-I nanodots is also highlighted. Our results exhibit a strong dependence of the negative trion binding energy on the core material size and the shell thickness, and on the core-to-shell band mismatch as well. The obtained data also show the opportunity of modulating the negatively charged exciton correlation energy in a broad range extending from 220 to 650 </span><span class="fontstyle2">meV </span><span class="fontstyle0">. That paves the way for new optoelectronic devices based on III-Nitride core/shell quantum dots.</span> </p> Ahmed CHAFAI I. Essaoudi A. Ainane C.A. Duque Copyright (c) 2023 Ahmed CHAFAI, I. Essaoudi, A. Ainane, C.A. Duque https://creativecommons.org/licenses/by-nc-nd/4.0 2023-09-19 2023-09-19 7 Theoretical study of structural phase transition and soft mode behavior in moganite http://caip.co-ac.com/index.php/materialsanddevices/article/view/161 <p>Changes in the structure and lattice dynamics of the moganite during crystal expansion were studied using ab initio calculations within the framework of density functional theory. The obtained results shed light on many anomalies in the temperature behavior of this crystal, such as the presence of a phase transition, soft mode condensation, elastic anomalies and negative thermal expansion. Comparison of the structural and dynamic properties of moganite and quartz opens up new possibilities for their identification in natural samples of mixed composition.</p> Mikhail Smirnov Dmitrii Pankin Eugene Roginskii Anastasia Povolotckaia Copyright (c) 2024 Mikhail Smirnov, Dr, Dr, Dr https://creativecommons.org/licenses/by-nc-nd/4.0 2024-02-08 2024-02-08 7 Book: Perovskites and other Framework Structure crystalline materials http://caip.co-ac.com/index.php/materialsanddevices/article/view/159 <p>Perovskites are among the most famous materials due to their exceptional properties : they<br>present nearly all existing types of ferroic and multiferroic properties (ferroelectric,<br>ferromagnetic, antiferroelectric, antiferromagnetic, magnetoelectric, etc), they may be<br>insulators, (super)conductors, or semiconductors, are used in numerous devices, they present<br>hundreds of variants and different crystalline phases, and recently appeared as probably the<br>most promising materials for photovoltaics. With a crystal structure characterized by octahedra<br>that share their corners, these materials belong to the wider category of « Framework Structure<br>(FWS) materials » the structure of which is based on units (octahedra, tetrahedra, ...) that<br>share some of their corners with their neighbours. This particular feature of FWS materials<br>confers to them unique properties.<br>This review volume is constituted of 26 chapters on different aspects, and is divided in two<br>parts, « Fundamental aspects and general properties », and « Elaborated materials and<br>applied properties ». Its main purpose is to attempt to identify the properties common to all<br>members of the vast family of FWS materials, and understand their differences. Besides<br>perovskites, derived compounds as 2D perovskites, Dion-Jacobson, Ruddlesden-Popper,<br>Aurivillius, tungsten-bronzes, and others, predominantly oxides, are presented, and their<br>preparation and/or properties as single crystals, ceramics, thin films, multilayers, nanomaterials,<br>nanofibers, nanorods, etc, are discussed. We focus on new trends and important recent<br>developments by leaving somewhat aside more classical aspects which can be easily found in<br>older textbooks or review articles.<br>Among most recent applications, this volume focuses on applications related with interactions<br>with other molecules, on photovoltaics, and on memories, with a special attention to perovskite<br>solar cells that have certainly attracted the most attention of researchers in recent years,<br>opening extremely promising routes in photovoltaics.<br>In conclusion, this book presents a collection of texts elucidating various aspects of the<br>phenomena related to the structural instabilities and singular properties of framework crystals ;<br>it proposes a reasonable balance between experimental and theoretical results, and between<br>fundamental aspects and applied properties.<br>This volume can be approached on several levels (each chapter initially assumes that the reader<br>is not a specialist in the subject, and is presented in a pedagogical way) : it is accessible to<br>master or doctoral students, as well as to researchers who want to enter the subject, or have<br>informations on recent developments, who will find excellent detailed introductions up to hot<br>subjects. It may also be used by undergraduate students who should approach given subjects. The volume contains 800 pages written by about 70 authors from different countries, it has an indexn and is completed by numerous figures to illustrate the text.</p> Pierre SAINT-GREGOIRE Mikhail B. Smirnov Copyright (c) 2023 Pierre SAINT-GREGOIRE, M.B. Smirnov https://creativecommons.org/licenses/by-nc-nd/4.0 2023-10-24 2023-10-24 7 Template for Opinion and Methods articles http://caip.co-ac.com/index.php/materialsanddevices/article/view/154 <p>Updated file to be used to write an Opinion article or a Methods article</p> Pierre Saint Gregoire Copyright (c) 2023 Pierre Saint Gregoire https://creativecommons.org/licenses/by-nc-nd/4.0 2023-12-05 2023-12-05 7 Standard template http://caip.co-ac.com/index.php/materialsanddevices/article/view/152 <p>Updated template to be used.</p> Pierre Saint Gregoire Copyright (c) 2023 Pierre Saint Gregoire https://creativecommons.org/licenses/by-nc-nd/4.0 2023-05-12 2023-05-12 7 Template http://caip.co-ac.com/index.php/materialsanddevices/article/view/153 <p>Updated template to be used for review articles.</p> Pierre Saint Gregoire Copyright (c) 2023 Pierre Saint Gregoire https://creativecommons.org/licenses/by-nc-nd/4.0 2023-05-12 2023-05-12 7 Real Solar Cell and Determination Methods of Electrical Parameters http://caip.co-ac.com/index.php/materialsanddevices/article/view/149 <p>In this work, we develop methods to determine the characteristic electrical parameters of a photovoltaic cell such as the photocurrent density (J<sub>ph</sub>), the saturation current density (J<sub>0</sub>), the short-circuit current density (J<sub>sc</sub>), the open-circuit voltage (V<sub>oc</sub>), the maximum power density point (J<sub>m</sub> , V<sub>m</sub>), the fill factor (FF) and the electrical conversion efficiency (eta<sub>C</sub>) according to the irradiance spectrum. The real solar cell model is considered for the determination of these various parameters. This model takes into account the effect of shunt and series resistances (parasitic resistances). Notions of semiconductor physics, continuity equation of charge carriers combined to optoelectronic and geometrical properties of the materials, numerical resolution method to solve implicit equations based on characteristic equation of a photodiode, are notions mainly exploited to determine electrical parameters of the real solar cell. The results are applied to the heterostructures ZnO(n<sup>+</sup>)/CdS(n)/CuInS<sub>2</sub>(p)/ CuInSe<sub>2</sub>(p<sup>+</sup>) named CIS and ZnO(n<sup>+</sup>)/CdS(n)/CuInSe<sub>2</sub>(p)/CuInS<sub>2</sub>(p<sup>+</sup>) named CISE to evaluate their performances according to the considered parameters. The results obtained for each structure, photocurrent density ~ 17 mA.cm<sup>-2</sup> (CIS) and 31 mA.cm<sup>-2 </sup>(CISE), short-circuit current density ~ 16.79 - 17 mA.cm<sup>-2</sup> (CIS) and 30.62 - 31 mA.cm<sup>-2</sup> (CISE), open-circuit voltage ~ 0.76 V (CIS) and 0.52 V (CISE), fill factor ~ 0.648 - 0.745 (CIS) and 0.545 - 0.677 (CISE), maximum power density ~ 8.28 - 9.69 mW.cm<sup>-2</sup> (CIS) and 8.72 - 11.02 mW.cm<sup>-2</sup> (CISE), saturation current ~ 4.117×10<sup>-8</sup> mA.cm<sup>-2</sup> (CIS) and 1.169×10<sup>-3</sup> mA.cm<sup>-2</sup> (CISE), are in the same magnitude order as the values published in the literature. We obtain under AM 1.5 solar spectrum and taken into account the parasitic resistances, a theoretical conversion efficiency ranging from 9.93% to 11.62% for the model CIS and from 10.46% to 13.22% for the model CISE. Thus, these results allow to validate the various models established to model the phenomena studied.</p> El Hadji Mamadou Keita F. Mbaye M. Dia C. Sow C. Sene B. Mbow Copyright (c) 2023 El Hadji Mamadou Keita, F. Mbaye, M. Dia, C. Sow, C. Sene, B. Mbow https://creativecommons.org/licenses/by-nc-nd/4.0 2023-05-12 2023-05-12 7 A critical view on citation index http://caip.co-ac.com/index.php/materialsanddevices/article/view/151 <p>This “opinion article” presents the “dialogue”, namely the series of questions addressed to chatGPT and its outputs, on the question of citation index and other metrics associated with scientific publication. The AI is asked to explain basic quantities (citation index, impact factor of journals, h-index, etc) and through different questions, to give outputs on different important problems, mainly related with citation index and its biases. The AI clearly expresses that the citation index alone should not be used for evaluation purposes, and is led to predict that in certain situations a high quality scientific article would be with a low citation index. The AI also replies that the citation index depends on several factors in a complex way, and is probably not defined in an unambiguous way from a mathematical point of view, but it appears unable to explain evolutions in the field of informetrics that occurred following issues with citation index. The article concludes that the citation index is irrelevant as it is not normalized and strongly depends on the publishing journal and databases, and that it is potentially dangerous for science.</p> P. Saint-Gregoire Copyright (c) 2023 P. Saint-Gregoire https://creativecommons.org/licenses/by-nc-nd/4.0 2023-05-12 2023-05-12 7