Synthesis and Optical Properties of One Year Air-Stable Chiral Sb(III) Halide Semiconductors

Chiral hybrid metal-halide semiconductors (MHS) pose as ideal candidates for spintronic applications owing to their strong spin-orbit coupling (SOC), and long spin relaxation times. Shedding light on the underlying structure-property relationships is of paramount importance for the targeted synthesis of materials with an optimum performance. Herein, we report the synthesis and optical properties of 1D chiral ( -/ -THBTD)SbBr (THBTD = 4,5,6,7-tetrahydro-benzothiazole-2,6-diamine) semiconductors using a multifunctional ligand as a countercation and a structure directing agent. ( -/ -THBTD)SbBr feature direct and indirect band gap characteristics, exhibiting photoluminescence (PL) light emission at RT that is accompanied by a lifetime of a few ns. Circular dichroism (CD), second harmonic generation (SHG), and piezoresponse force microscopy (PFM) studies validate the chiral nature of the synthesized materials. Density functional theory (DFT) calculations revealed a Rashba/Dresselhaus (R/D) spin splitting, supported by an energy splitting ( ) of 23 and 25 meV, and a Rashba parameter (α ) of 0.23 and 0.32 eV·Å for the and analogs, respectively. These values are comparable to those of the 3D and 2D perovskite materials. Notably, ( -THBTD)SbBr has been air-stable for a year, a record performance among chiral lead-free MHS. This work demonstrates that low-dimensional, lead-free, chiral semiconductors with exceptional air stability can be acquired, without compromising spin splitting and manipulation performance

One-Year Water-Stable and Porous Bi(III) Halide Semiconductor with Broad-Spectrum Antibacterial Performance

Hybrid metal halide semiconductors are a unique family of materials with immense potential for numerous applications. For this to materialize, environmental stability and toxicity deficiencies must be simultaneously addressed. We report here a porous, visible light semiconductor, namely, (DHS)Bi2I8 (DHS = [2.2.2] cryptand), which consists of nontoxic, earth-abundant elements, and is water-stable for more than a year. Gas- and vapor-sorption studies revealed that it can selectively and reversibly adsorb H2O and D2O at room temperature (RT) while remaining impervious to N2 and CO2. Solid-state NMR measurements and density functional theory (DFT) calculations verified the incorporation of H2O and D2O in the molecular cages, validating the porous nature. In addition to porosity, the material exhibits broad band-edge light emission centered at 600 nm with a full width at half-maximum (fwhm) of 99 nm, which is maintained after 6 months of immersion in H2O. Moreover, (DHS)Bi2I8 exhibits bacteriocidal action against three Gram-positive and three Gram-negative bacteria, including antibiotic-resistant strains. This performance, coupled with the recorded water stability and porous nature, renders it suitable for a plethora of applications, from solid-state batteries to water purification and disinfection

Hydrothermal synthesis of ZnO nanowires for photovoltaic application

National audiencePV technologies have emerged as alternative to the first (silicon) and second generation (semiconducting inorganic materials) solar cellsexpecting to lead to less expensive devices. Perovskite (organometallic), all organic (OPV) and organic/inorganic (called hybrid PhotovoltaicHPV) are developed specifically for nomad applications. HPV emerging materials have a special interest because they combine the low costand large scale production advantages of polymers with the charge carrier mobility and the chemical stability of the inorganic materials. Theactive layers of hybrid or organic PV cells are always made with the combination of two distinct components, namely, the electron-accepting(acceptor A) and the hole-accepting (donor D) materials. The nature of these materials has already been varied a lot, with π-conjugatedpolymers, fullerene C60 or C70 derivatives (OPV technology) or organometallic (Perovskite technology), and ZnO thin layers or ZnO nanowires.This work aims at developing of semitransparent architectured tandem 2.5/3 D hybrid photovoltaic solar cells using semitransparentmonolithic (not two separate cells interconnected) tandem cell based on nano-architectured ZnO directly growth on the substrate byhydrothermal route. A nano-structuration of D or D/A and ZnO nanowires close to the ideal interpenetrating D/A system is targete

A key progress in introducing single walled carbon nanotubes to photovoltaic devices

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Hydrophobic copolymers with flexible surface properties for highly functional industrial polymers

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Extrusion as plausible processing method for production of organic photovoltaic solar cells

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Effect of temperature and initiator on glass fibre/unsaturated polyester composite : cross-linking, mechanical properties

The influence of temperature (20–60°C) and initiator ratio (1–3%) on the cross- linking and mechanical properties of the matrix resin and of gla ss fibre/unsaturated polyester composite; prepared by hand lay-up process and us ed in marine structures, is studied. Reactivity tests have shown that the effect of temperature in crease is similar to that of initiator ratio. They increase reaction rate and reduce the gelation tim e and exothermic peak. Conversely, the Fourier transform infrared spectroscopy analyses have sh own that the final conversions of styrene and polyester vinyl groups are almost co mplete, and that whatever the chosen operating conditions. Tensile and bending tests have shown that the m echanical properties (Elastic modulus, tensile strength...) are optimal for the samples operated at 40°C with 1% of initiator and those operated at 20°C with 2% of initiato

Hydrophobic copolymers with flexible surface properties for highly functional industrial polymers

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Custom Synthesis of ZnO Nanowires for Efficient Ambient Air-Processed Solar Cells

International audienceNanostructuration of solar cells is an interesting approach to improve the photovoltaic conversion efficiency (PCE). This work aims at developing architectured 3D hybrid photovoltaic solar cells using ZnO nanowires (ZnONWs) as the electron transport layer (ETL) and nanocollectors of electrons within the active layer (AL). ZnONWs have been synthesized using a hydrothermal process with a meticulous control of the morphology. The AL of solar cells is elaborated using ZnONWs interpenetrated with a bulk heterojunction composed of donor (π-conjugate low band gap polymer: PBDD4T-2F)/acceptor (fullerene derivate: PC71BM) materials. An ideal interpenetrating ZnONW-D/A system with predefined specific morphological characteristics (length, diameter, and inter-ZnONW distances) was designed and successfully realized. The 3D architectures based on dense ZnONW arrays covered with conformal coatings of AL result in an increased amount of the ETL/AL interface, enhanced light absorption, and improved charge collection efficiency. For AL/ZnONW assembly, spin-coating at 100 °C was found to be the best. Other parameters were also optimized such as the D/A ratio and the pre/post-treatments achieving the optimal device with a D/A ratio of 1.25/1 and methanol treated on ZnONWs before and after the deposition of AL. A PCE of 7.7% (1.4 times better than that of the 2D cells) is achieved. The improvement of the performances with the 3D architecture results from both of: (i) the enhancement of the ZnO/AL surface interface (1 μm2/μm2 for the 2D structure to 6.6 μm2/μm2 for the 3D architecture), (ii) the presence of ZnONWs inside the AL, which behave as numerous nanocollectors (∼60 ZnONW/μm2) of electrons in the depth of the AL. This result validates the efficiency of the concept of nanotexturing of substrates, the method of solar cell assembly based on the nano-textured surface, the chosen morphological characteristics of the nanotexture, and the selected photoactive organic materials

Optimized stoichiometry for CuCrO2 thin films as Sustainable and semi-transparent Hole Transparent Layer in performant and recyclable organic solar cells

International audienc