Arsole‐containing conjugated polymers are a practically unexplored class of materials despite the high interest in their phosphole analogues. Herein we report the synthesis of the first dithieno[3,2‐b;2′,3′‐d]arsole derivative, and demonstrate that it is stable to ambient oxidation in its +3 oxidation state. A soluble copolymer is obtained by a palladium‐catalyzed Stille polymerization and demonstrated to be a p‐type semiconductor with promising hole mobility, which was evaluated by field‐effect transistor measurements.

Materials such as W, TiN, and SrRuO (SRO) have been suggested as promising alternatives to Au and Ag in plasmonic applications owing to their stability at high operational temperatures. However, investigation of the reproducibility of the optical properties after thermal cycling between room and elevated temperatures is so far lacking. Here, thin films of W, Mo, Ti, TiN, TiON, Ag, Au, SrRuO and SrNbO are investigated to assess their viability for robust refractory plasmonic applications. These results are further compared to the performance of SrMoO reported in literature. Films ranging in thickness from 50 to 105 nm are deposited on MgO, SrTiO and Si substrates by e-beam evaporation, RF magnetron sputtering and pulsed laser deposition, prior to characterisation by means of AFM, XRD, spectroscopic ellipsometry, and DC resistivity. Measurements are conducted before and after annealing in air at temperatures ranging from 300 to 1000° C for one hour, to establish the maximum cycling temperature and potential longevity at elevated temperatures for each material. It is found that SrRuO retains metallic behaviour after annealing at 800° C, while SrNbO undergoes a phase transition resulting in a loss of metallic behaviour after annealing at 400° C. Importantly, the optical properties of TiN and TiON are degraded as a result of oxidation and show a loss of metallic behaviour after annealing at 500° C, while the same is not observed in Au until annealing at 600° C. Nevertheless, both TiN and TiON may be better suited than Au or SRO for high temperature applications operating under vacuum conditions.

By decoupling the mechanical behaviour of building units for the first time in a wine-rack framework containing two different strut types, we show that lithium l-tartrate exhibits NLC with a maximum value, K = -21 TPa, and an overall NLC capacity, χ = 5.1%, that are comparable to the most exceptional materials to date. Furthermore, the contributions from molecular strut compression and angle opening interplay to give rise to so-called "hidden" negative linear compressibility, in which NLC is absent at ambient pressure, switched on at 2 GPa and sustained up to the limit of our experiment, 5.5 GPa. Analysis of the changes in crystal structure using variable-pressure synchrotron X-ray diffraction reveals new chemical and geometrical design rules to assist the discovery of other materials with exciting hidden anomalous mechanical properties.

The dependence of charge carrier mobility on semiconductor channel thickness in field‐effect transistors is a universal phenomenon that has been studied extensively for various families of materials. Surprisingly, analogous studies involving metal oxide semiconductors are relatively scarce. Here, spray‐deposited In2O3 layers are employed as the model semiconductor system to study the impact of layer thickness on quantum confinement and electron transport along the transistor channel. The results reveal an exponential increase of the in‐plane electron mobility (µe) with increasing In2O3 thickness up to ≈10 nm, beyond which it plateaus at a maximum value of ≈35 cm2 V−1 s−1. Optical spectroscopy measurements performed on In2O3 layers reveal the emergence of quantum confinement for thickness <10 nm, which coincides with the thickness that µe starts deteriorating. By combining two‐ and four‐probe field‐effect mobility measurements with high‐resolution atomic force microscopy, it is shown that the reduction in µe is attributed primarily to surface scattering. The study provides important guidelines for the design of next generation metal oxide thin‐film transistors.

Strontium molybdate (SrMoO3) thin films are grown epitaxially on strontium titanate (SrTiO3), magnesium oxide (MgO), and lanthanum aluminate (LaAlO3) substrates by pulsed laser deposition and possess electrical resistivity as low as 100 µΩ cm at room temperature. SrMoO3 is shown to have optical losses, characterized by the product of the Drude broadening, ΓD, and the square of the plasma frequency, ωpu2, significantly lower than TiN, though generally higher than Au. Also, it is demonstrated that there is a zero‐crossover wavelength of the real part of the dielectric permittivity, which is between 600 and 950 nm (2.05 and 1.31 eV), as measured by spectroscopic ellipsometry. Moreover, the epsilon near zero (ENZ) wavelength can be controlled by engineering the residual strain in the films, which arises from a strain dependence of the charge carrier concentration, as confirmed by density of states calculations. The relatively broad tunability of ENZ behavior observed in SrMoO3 demonstrates its potential suitability for transformation optics along with plasmonic applications in the visible to near infrared spectral range.

Arsole-containing conjugated polymers are apractically unexplored class of materials despite the high interest in their phosphole analogues.H erein we report the synthesis of the first dithieno [3,2-b;2',3'-d]arsole derivative,a nd demonstrate that it is stable to ambient oxidation in its + 3oxidation state.Asoluble copolymer is obtained by ap alladiumcatalyzedS tille polymerization and demonstrated to be a p-type semiconductor with promising hole mobility,which was evaluated by field-effect transistor measurements.Since the first reports of the metallic behavior of conjugated polymers (CPs), the development of new materials has been at the forefront of research in plastic electronics. [1,2] The enormous scope to tune their optoelectronic characteristics and device performance by the copolymerization of different monomeric units is appealing for many applications.[3] In recent years,t here has been ag rowing interest in the incorporation of heavier elements-silicon and germanium in Group 14, phosphorus in Group 15, selenium and tellurium in Group 16-as replacements for lighter elements,s uch as carbon, nitrogen, and sulfur,i nC Ps. [4][5][6][7] Their use has been shown to have as ignificant impact on the polymer band gap and energy levels,a sw ell as the solid-state packing.[8] The inclusion of heavy atoms can also facilitate intersystem crossing, leading to the rapid conversion of singlet excitons into triplets,and can lead to solid-state phosphorescence. [9,10] Among the CPs containing Group 15 elements,t hose incorporating ad ithienometallole ( have seen application in all major areas of plastic electronics. [11][12][13] Thei nterest in DTPs partially arises from their high electron affinity,which results from the s-p hyperconjugation exhibited by the phosphole ring, whereby the s*orbital of the exocyclicP À Cbond is able to interact with the p*orbitals of the fused heterocycle.[14] Furthermore,m odification of the P lone pair, through reactions with either Lewis acids or oxidizing agents,c an further tune the energy levels. [15] However,asphosphole derivatives are prone to uncontrolled oxidation in ambient atmosphere,t he phosphole oxide is often deliberately formed to prevent uncontrolled aging. [16] As such, the properties of the unoxidized phospholes are rarely reported.Inspired by the fascinating properties of DTP,w ew ere interested in preparing the heavier analogue containing ab ridging arsenic atom. Of particular interest was the fact that arsenic-containing compounds are typically more difficult to oxidize to the + 5o xidation state than their P analogues. [17][18][19] This is related to the poor shielding of the filled 3d orbitals in As,such that the selectrons are relatively tightly bound compared to those in the corresponding phosphorus-based compounds.T herefore,a rsole-containing polymers may be intrinsically more resistant to ambient oxidation than their phosphole equivalents,a llowing the properties of the heterocycle in the + 3oxidation state to be explored. As far as we are aware,t...

The aqueous processed ZnO ETLs enable low-temperature, simple and green-strategy fabrication for efficient OPVs and OLEDs.

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