Two novel alkyl thiophene-modified pyrene derivatives (1)-(2) were created and synthesized using palladium-catalyzed Stille coupling processes and Friedel-Crafts reaction of pyrene. The polycyclic aromatic groups of the thiophene-modified pyrene were oxidized with Ag[Al(OC(CF3)3)4] to provide the insensitive radical cations 1•+-2•+ based on the alkyl thiophene-modified pyrene derivatives. Nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), UV-Vis spectroscopy, and density functional theory (DFT) calculations, were used to investigate their structures and properties. The pyrene moieties were the primary location of the electron spin distribution, with a little overflow onto the outer thiophene moieties. Due to the different substituent groups, free radicals 1•+ 2•+ exhibit some different properties. Compound 1•+ is the most extensive thiophene-modified pyrene radical cation that has been reported. These species are anticipated to have wide-ranging potential in the areas of optoelectronic materials and semiconductors. thiophenemodified modified 12 1 2 (1)-(2 palladiumcatalyzed palladium catalyzed FriedelCrafts Friedel Crafts AgAlOCCF334 AgAlOCCF Ag Al OC CF3 3 4 CF Ag[Al(OC(CF3)3)4 1•+2•+ 1•+-2• NMR, NMR , (NMR) EPR, EPR (EPR) UVVis UV Vis spectroscopy DFT (DFT calculations properties distribution 1• 2• reported wideranging wide ranging semiconductors (1)-( AgAlOCCF33 Ag[Al(OC(CF3)3) 1•+2• 1•+-2 (NMR (EPR (1)- AgAlOCCF3 Ag[Al(OC(CF3)3 1•+2 1•+- (1) Ag[Al(OC(CF3) (1 Ag[Al(OC(CF3 ( Ag[Al(OC(CF

Resumen: Este trabajo de revisión se centra en la producción fotocatalítica de hidrógeno empleando agentes de sacrificio y semiconductores modificados con nanopartículas metálicas. Mientras que el uso de agentes de sacrificio reduce la energía requerida para la producción de hidrógeno y elimina los huecos fotogenerados, la modificación superficial de los semiconductores con nanopartículas metálicas cambia el flujo de los portadores de carga fotoinducidos, disminuyendo la recombinación de los pares electrón-hueco y aumentando la cantidad de sitios activos catalíticos para la reducción. Además, se describe el impacto de las técnicas electroquímicas y fotoelectroquímicas en la caracterización de los fotocatalizadores, la interfase semiconductor/electrolito y la modificación que tiene el nivel de Fermi cuando se ponen en contacto estos componentes. Dichas determinaciones electroquímicas brindan información sobre el diagrama de bandas (posiciones de banda de valencia y/o de conducción), estados energéticos del semiconductor, interacción del fotocatalizador con los co-catalizadores, separación de las especies electrón-hueco, aprovechamiento de la iluminación y resistencia a la transferencia de carga. La relación de la actividad fotocatalítica de los semiconductores y su caracterización electroquímica permite comprender los procesos de transferencia de carga involucrados en dicha reacción.

Abstract: This review paper focuses on photocatalytic hydrogen production using sacrificial agents and semiconductors modified with metal nanoparticles. While the use of sacrificial agents reduces the energy required for hydrogen production and eliminates the recombination of photogenerated holes, the surface modification of semiconductors with metal nanoparticles changes the flow of photoinduced charge carriers, decreasing the recombination of electron-hole pairs and increasing the number of catalytic active sites for reduction. In addition, the impact of electrochemical and photoelectrochemical techniques on the characterization of the photocatalysts, the semiconductor/electrolyte interface, and the modification of the Fermi level when these components are in contact is described. These electrochemical determinations provide information on the band diagram (valence and/or conduction band positions), energy states of the semiconductor, interaction of the photocatalyst with the co-catalysts, separation of the electron-hole species, use of illumination, and resistance to charge transfer. Establishing a relationship between the photocatalytic activity of semiconductors and their electrochemical characterization allows understand the charge transfer processes involved in such a reaction.

Resumo O presente artigo tem por objetivo resgatar a história de milhares de mulheres operárias que lutaram pelo direito ao trabalho e por melhores condições de vida durante o período revolucionário português. Escolhemos, enquanto objeto de análise, o setor da produção de componentes eletrónicos onde a força de trabalho era maioritariamente feminina. Para este fim, selecionamos sobretudo as fábricas do grupo ITT - Standard Elétrica e Semicondutores -, Plessey e Applied Magnetics. Com o 25 de Abril de 1974, as possibilidades de mudança eram latentes e foram experimentadas pela classe trabalhadora, ainda que a historiografia deste período seja predominantemente masculina. Contrariando essa perceção, destacamos como as mulheres não apenas participaram, mas foram agentes ativas nas lutas desencadeadas nos diversos espaços sociais com destaque para os confrontos fabris.

Abstract This article intends to rescue the history of thousands of women workers who fought for the right to work and for better living conditions during the Portuguese revolutionary period. We have chosen as object of analysis the sector of electronic components production, where the workforce was mostly women. For this purpose, we mainly selected the factories of the ITT group - Standard Electrical and Semiconductors -, Plessey and Applied Magnetics. With April 25, 1974, the possibilities for change were latent and were experienced by the working class, even though the historiography of this period is predominantly male. Contrary to this perception, we highlight how women not only participated, but were active agents in the struggles unleashed in the various spaces, with emphasis on the factory confrontations.

Lead-free halide double perovskites with the formula A2BIBIIIX6, and ordered vacancy perovskites, with the general formula A2BIVX6 have recently emerged as alternative materials for advancements in lead-halide perovskites. While the main obstacles to the development of lead-halide perovskites are the use of lead and the instability of the structure, halide double perovskites allow multiple metal combinations resulting from the replacement of the lead in single perovskites by two metal-complexes or alternating vacancy metal-complexes in their crystalline structure. Although many advances have already been made in lead-free halide double perovskites, there are still some challenges to be overcome, such as the indirect and high bandgap, and the transitions prohibited by parity, which are intrinsic features of their electronic structure, and result in low energy conversion efficiency and photoluminescence quantum yields as well. Emphasizing the need to review the results of the literature so far, considering the advances and challenges presented, this work involves a systematic and embracing bibliographical research on lead-free halide double perovskites, encompassing central aspects such as their historical evolution, crystalline structure, synthesis methods, challenges faced in the field, optoelectronic properties and perspectives for the development and application of these materials. Leadfree Lead free A2BIBIIIX6 ABIBIIIX A BIBIIIX ABIVX BIVX A2BIVX leadhalide structure metalcomplexes complexes leadfree overcome bandgap parity well far presented evolution methods field A2BIBIIIX

Metallic nanoparticles remain the focus of diverse studies across various fields due to their exceptional properties and applications in biology, sensing, energy, and (electro)catalysis. Typical syntheses of metallic nanoparticles are solution-based and require the use of stabilizing agents. Although these surface agents prevent agglomeration, they also hinder access to active sites on the nanoparticle surface. A promising alternative is mechanochemical synthesis, offering a solvent and surfactant-free approach, which yields uniform nanoparticles with clean surfaces. Here, we employ ball milling as a mechanochemical method to prepare metallic bismuth nanoparticles in a single step, using BiVO4 semiconductor both as a bismuth source and a support. Our results demonstrate that, in addition to the formation of nanoparticles by the partial reduction of BiVO4, there is an increase in charge carriers in the semiconductor structure as probed by electrochemical experiments. The final properties of Bi@BiVO4 material make it a relevant candidate for (electro)catalysis. biology sensing energy electrocatalysis. electrocatalysis electro catalysis. catalysis (electro)catalysis solutionbased solution based agglomeration synthesis surfactantfree surfactant free approach surfaces Here step BiVO support that experiments BiBiVO4 BiBiVO Bi Bi@BiVO

Austenitic and lean duplex stainless steels, such as AISI 317L and SAF 2304, present high mechanical and corrosion resistance, which make them alternative materials for biodiesel plant equipment. Because there is not sufficient research about these stainless steel-specific applications, this work aims to evaluate AISI 317L and SAF 2304 stainless-steel pitting corrosion resistance in a chloride-containing acidified glycerin solution, collected directly from a biodiesel plant. The SAF 2304 presented a higher pitting potential than the AISI 317L, at room temperature and at service temperature, 337 K. However, the SAF 2304 passive layer was more reactive than the AISI 317L, showing a higher passive current density in the polarization and chronoamperimetric tests. Furthermore, the Mott–Schottky technique showed that the passive layer of the AISI 317L steel contained a lower concentration of defects than the passive layer of the SAF 2304, and the oxides of the passive layers are n-type semiconductors. steels L equipment steelspecific specific applications 230 stainlesssteel chloridecontaining chloride containing solution 33 K However tests Furthermore MottSchottky Mott Schottky ntype n type semiconductors 23 3 2

It is essential to diversity energy sources for ensuring sustainability. While hydrogen is considered a promising energy storage medium, its potential hinges on the development of efficient photocatalysts for green production. In addressing this challenge, we evaluated the performance of a heterojunction system composed of non-stoichiometric molybdenum oxides (MoO3−x) and cadmium sulfide (CdS) quantum dots (QDs) for water splitting. MoO3−x were synthesized via gamma irradiation of the MoO3 in the presence of formic acid (FA), while CdS-MPA QDs were electrosynthesized. The heterojunction was formed through adsorption. The structural and electronic characterization revealed a progressive transformation from MoO3 to MoO3−x and MoO3−x/CdS-MPA QDs, demonstrating enhanced water-splitting performance. Upon evaluation, the study revealed a charge transfer mechanism, highlighting the significance of relative band positions between MoO3−x and CdS-MPA QDs in promoting eco-friendly hydrogen evolution and methanol processing. Thus, we suggest that the synergism between MoO3−x and CdS-MPA QDs semiconductors makes the heterojunction system a promising solution for photocatalytic production of hydrogen and oxygen. sustainability medium challenge nonstoichiometric non stoichiometric MoO3x MoOx x MoO (MoO3−x CdS (CdS (QDs splitting FA, FA , (FA) CdSMPA MPA electrosynthesized adsorption MoO3−x/CdSMPA MoO3xCdSMPA MoOxCdSMPA MoO3−x/CdS watersplitting evaluation mechanism ecofriendly eco friendly processing Thus oxygen (FA xCdSMPA MoO3xCdS MoOxCdS xCdS

Titanium dioxide (TiO2) is an n-type oxide semiconductor, where the electron donors are usually associated with oxygen vacancies and interstitial titanium ions, whereas quinoline derivatives (QD) are usually p-type semiconductors with light emission in the blue range. We report a broad emission band centered at 485 nm, and temperature induced electrical properties of the QD 4-(6-(diethylamino)-4-phenylquinolin-2-yl)benzoic acid and TiO2 films. The combination of QD with TiO2, both layers in the form of thin film, forms a heterostructure in a very convenient format for integration in optoelectronics. Due to the techniques used for film deposition, both sort of films present defects, which are responsible for the electrical characteristics. The dominant level for TiO2 is located about 760 meV from the conduction band bottom, inside the bandgap, whereas for the QD film the activation energy is about 328 meV. Both levels show up for a range above room temperature. In the first case, it suggests the second ionization level of oxygen vacancies (VO2+) or the third ionization level of interstitial titanium ions (Ti3+), considering that both are electron donors, whereas in the case of QD it suggests a mechanism of small polaron tunneling (SPT).When combined as a heterostructure and explored under transport profile perpendicular to the films (transverse contacts) it leads to current-voltage (I-V) rectifying behavior similar to a p-n junction, which is evidence of the p-type-like electrical behavior of the QD, even though this I-V behavior may be destroyed for repetitive I-V measurement, which seems to be related with aging and the presence of defects at the heterostructure interface. TiO (TiO2 ntype n type semiconductor (QD ptype p 48 nm 46diethylamino4phenylquinolin2ylbenzoic diethylaminophenylquinolinylbenzoic 4 6 diethylamino phenylquinolin 2 yl benzoic optoelectronics deposition characteristics 76 bottom bandgap 32 VO2+ VO2 VO (VO2+ Ti3+, Ti3 Ti Ti3+ , (Ti3+) SPT.When SPTWhen SPT .When When transverse contacts currentvoltage current voltage IV I V (I-V pn junction ptypelike like measurement interface (TiO ylbenzoic 7 3 (VO2 (Ti3+ (VO (Ti3 (Ti

ABSTRACT This review article provides a concise view of the transformative role played by silicon carbide (SiC) semiconductors in the electric power industry, along with a description of their emerging applications in electric vehicles (EVs), renewable energy systems, aeronautics, and space. It highlights SiC chips’ ability to operate at high temperatures and frequencies, surpassing the limitations of traditional silicon chips and resulting in enhanced efficiency. Additionally, it also presents the capabilities of SiC devices to manage elevated power levels within reduced size and weight parameters, emphasizing their impact on augmenting power density in EVs and enhancing reliability and efficiency in renewable energy, aeronautics, and space applications. Finally, the review concludes by providing an overview of the prevailing trends, existing challenges, and the future trajectory of SiC semiconductors within these important sectors. (SiC industry EVs, , (EVs) systems aeronautics frequencies Additionally parameters Finally trends challenges sectors (EVs

Resumo No contexto de pandemia do Covid-19, a cadeia automotiva no Brasil foi impactada pela indisponibilidade de semicondutores - microchips utilizados na produção de automóveis e de equipamentos eletrônicos, cujo consumo vem também produzindo impactos nos mercados de automóveis e autopeças. Este artigo objetiva analisar transformações recentes no setor, tomando como mote os deslocamentos contemporâneos na circulação desse componente. Tal análise partirá de dois contextos empíricos distintos: o Porto de Santos e um desmanche de veículos em São Paulo. Argumentamos que as transformações em tela devem ser compreendidas no cruzamento entre mobilidades físicas e comunicativas, apontando para importantes inflexões na cadeia automotiva em escala transnacional. Covid19, Covid19 Covid 19, 19 Covid-19 eletrônicos autopeças setor componente distintos Paulo comunicativas transnacional Covid1 1 Covid-1 Covid-

Abstract During the Covid-19 pandemic, the scarcity of semiconductors affected the automotive chain in Brazil. The production electronic devices in general, whose consumption also impacts the automotive market, depends on these microchips. This article aims to analyze recent displacements in the automobile system, through contemporary transformations in the circulation of this component. This analysis is based on ethnographic data produced in the Santos Port and a car dismantling store in São Paulo. We argue that such transformations must be understood at the intersection between physical and communicative mobilities which reverberates around the automotive chains in a transnational scale. Covid19 Covid 19 Covid-1 pandemic Brazil general market microchips system component Paulo scale Covid1 1 Covid-

Abstract In this work, the influences of biaxial compressive and tensile strains on optical gain and threshold current density are investigated theoretically as a function of the side lengths of the quantum box in the GaN/Al0.2Ga0.8N structure by using a model based on the density matrix theory of semiconductor lasers with relaxation broadening. For various side lengths of the quantum box, we compare the spectra gain curves of compressive, tensile-strained, and unstrained structures of the GaN/Al0.2Ga0.8N cubic quantum-dot (QD) laser. The dependence of peak optical gain on carrier density and the modal gain on current density is plotted too for all cases. The results reveal that many enhancements can be made to the laser structure by introducing - 0.5 % compressive strain: a higher value of optical gain of 18421 cm-1 at L = 60 Å, a lower value of transparency of carrier density of N t r = 0.13 × 1 0 19 cm-3 and transparency current density of J t r = 26.9 A/cm2 and a lower threshold current density of J t h = 78.87 A/cm2 at L = 100 Å.

Abstract For oxide semiconductors for application in dye-sensitized solar cells (DSSCs), titanium dioxide conjugated with zinc oxide thin films was synthesized and characterized. The UV (ultraviolet) spectrum characterization showed a peak of absorbance at around 355 nm, with a band gap of 3.25 eV and reflectance around 85%. Such characteristics allowed the fabrication of DSSCs with N719 dye, under simulated light of 100 mW/cm2. The highest efficiency of 1.17% was at 5% titanium dioxide and 4 h of dye immersion. dyesensitized sensitized DSSCs, , (DSSCs) characterized ultraviolet (ultraviolet 35 nm 325 3 25 3.2 85 85% N N71 10 mWcm2 mWcm mW cm2 cm mW/cm2 117 1 17 1.17 5 immersion (DSSCs 32 2 3. 8 N7 mW/cm 11 1.1 1.

Abstract In this paper, on the basis of first-principles, the CASTEP module of Materials Studio is used to calculate the band structures and optical properties of CuFeSe2 and CuFeS2 under the PBE pseudopotential of the generalized gradient approximation (GGA). The calculated results show that both CuFeSe2 and CuFeS2 are direct bandgap semiconductors with forbidden band widths of 0.64 eV and 1.06 eV, respectively. In the visible light range, the highest absorption coefficient of CuFeSe2 is 1.082×105 cm-1, the average reflectivity is 0.52, the maximum conductivity is 7.23 fs-1, the electrostatic constant is 65.9; the maximum value the highest absorption coefficient of CuFeS2 is 0.872×105 cm-1, the average reflectivity is 0.44, the maximum conductivity is 4.44 fs-1, the static dielectric constant is 52.32. The calculation results in this paper show that compared with CuFeS2, CuFeSe2 has advantages in photoconductivity and carrier separation, but has disadvantages in band gap and reflectivity. It is recommended to combine the two materials to prepare tandem solar cells. firstprinciples, firstprinciples first principles, principles first-principles CuFeSe CuFeS GGA. GGA . (GGA) 064 0 64 0.6 106 1 06 1.0 respectively range 1082105 082 105 1.082×10 cm1, cm1 cm 1, cm-1 052 52 0.52 723 7 23 7.2 fs1, fs1 fs fs-1 65.9 659 65 9 0872105 872 0.872×10 044 44 0.44 444 4 4.4 5232 32 52.32 separation cells (GGA 6 0. 10 1. 108210 08 1.082×1 cm- 05 5 0.5 72 2 7. fs- 65. 087210 87 0.872×1 04 0.4 4. 523 3 52.3 10821 1.082× 08721 8 0.872× 52. 1082 1.082 0872 0.872 108 1.08 087 0.87 0.8

Poly(vinyl chloride) (PVC) is considered one of the most versatile polymers due to its interaction with different additives. On the other hand, binary sulfides have wide applications as zinc sulfide (ZnS), one of the first discovered semiconductors. This study aims to synthesize a nanocomposite material containing nano ZnS in the PVC matrix with a surfactant as a compatibilizer agent to evaluate its optical and electrical properties when exposed to gamma radiation. Our results showed that adding ZnS at 0.5 wt% concentration in the PVC matrix promoted the system from insulating to the semiconductor material. Therefore, gamma radiation has played an important role in nanocomposites' optical and electrical properties with changes in electrical and electrical conductivity, constant dielectric parts, refraction index, optical band gap, and Urbach energy. Thus, our study points to the development of nanocomposite material, semiconductors, and features useful for applications in flexible electronics or optical-electronic devices. Polyvinyl Poly vinyl chloride (PVC additives hand ZnS, , (ZnS) semiconductors 05 0 5 0. wt Therefore nanocomposites conductivity parts index gap energy Thus opticalelectronic electronic devices (ZnS

The aim of the present study is to create the guided inquiry laboratory works in studying the photoelectric properties of semiconductors in order to foster the students’ research experiences. In this context, the general structure of guided inquiry laboratory work is proposed and described. Each laboratory work includes preparation section, experiment section, interpretation section and consolidation section. Two created laboratory works include five experimental investigations in luminous and current-voltage characteristics of CdS photoresistors, selenium and silicon solar cells. The use of self-made equipment allows students to be introduced to the general principles of creating installation for these experimental investigations. The advantages and possibilities of self-made device for studying the photoelectric properties of semiconductors have been formulated. The design of the device allows changing the illumination of the photodetectors, measure dark currents, determining the photocurrent, calculate the sensitivity of photodetectors, confirm sublinear law for photoresistors, and study the current-voltage characteristics for different luminous flux. The cost of manufacturing the device is quite low. The questions to consolidate knowledge are offered for each laboratory work. Described general method of performing guided inquiry laboratory work could be used in the study of other topics of physics. Proposed level of inquiry-based learning is successfully used by the authors of the present article during professional training of Bachelor’s and Master’s students, future physics teachers.