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We demonstrate a new class of cyclotriguaiacyclene-functionalized trans cinnamate based supramolecular compounds with room temperature columnar liquid crystalline properties suitable as eco-friendly constituent layers in third generation solar cells.

Lower-rim functionalized resorcinarene-based supramolecular compounds with a columnar hexagonal phase are designed for high-temperature LCs for application as optical window and tranposrt layer in solar cells.

Solar energy may cater current power demand and second generation with modified technologies could play important role. This review presents role of ZnTe as efficient interface to CdTe devices with future road map to improve device performance.

The CdTe solar cell engineering is still lacking maximum achievable power conversion efficiency as predicted based upon the detailed balance. In device development, each constituent layer plays important role and to reduce open-circuit voltage loss, the reduction of back surface recombination is a promising approach. It could be made by introducing a wide-band gap ZnTe layer between the absorber CdTe layer and metal contact which can solve the issue of the Schottky barrier at the interface. The ZnTe layers also need optimization to the physical properties to implicate in CdTe-based device and therefore, the present work reports annealing and thickness evolution to ZnTe films to seek their feasibility as rear contact material where 200 nm and 300 nm thin ZnTe films are developed employing e-beam evaporation and subsequently annealed at 100 °C, 200 °C and 300 °C in air ambient followed by characterizations by amicable tools for exploration of relevant physical properties. Findings demonstrate that the film thickness and annealing temperature have considerably affected the physical properties of the developed films and the 200 nm ZnTe thin films annealed at 100 °C may be implicated as rear contact material in CdTe solar cell devices.

As the cracking mode (tensile or shear) of a crack is related to the underlying physical mechanisms, crack mode classification is a very useful method to identify the damage state of a structure for proper maintenance to enhance structural safety and durability. Acoustic Emission (AE) is a passive structural health monitoring technique based on the stress wave generated due to cracking in a structure. A framework has been designed in this study for automated probabilistic classification of the cracks in cementitious components based on the AE signals. With this approach, unlabeled hand designed waveform parameters, i.e. RA values (RA) and Average frequency (AF) are clustered using density dictated unsupervised clustering algorithm. Intersecting clusters in the data were then separated through a hyperplane created using Support Vector Machine (SVM) algorithm. Based on physical insight obtained from labeled data, unlabeled data was classified into events corresponding to different cracking modes. The framework was applied to the analysis of AE data from Steel Fiber Reinforced Concrete (SFRC) beam under bending and Strain Hardening Cementitious Composite (SHCC) samples under direct tension. The cracking modes obtained from the proposed machine learning approach are found to be in good agreement with expectations based on composite theory. With good qualitative prediction, the proposed approach shows promise for the prediction of damage state in structures based on unlabeled data obtained in the field.

In this study, the synthesis, structural characterization and mesomorphic properties of newly thirteen calamitic shaped compounds derived from allylidene amino chalcone and 4-n-alkoxy benzoyloxy benzoic acid. Comp.H1 to H3 exhibited nonliquid crystalline nature, while comp.H4 to comp.H18 displayed enantiotropical smectic C phase. Phase transition temperatures of present synthesised compounds were determined by optical polarising microscopy (POM), differential scanning calorimetric (DSC) and powder X-ray diffraction (PXRD) techniques. Thermal stabilities of smectic to isotropic phase are 150.0 °C and temperature range of mesophase is in decreasing order from comp.H3 to comp.H18 respectively. The presences of SmC phase are the type of broken fan and needle type in present synthesized series. It is also shown that presence of chalcone amino allylidene central linking group favors a calamitic liquid crystalline behaviour in molecules with lower member to higher member aliphatic side chain in alkoxy gr...

In present study, we have synthesized two newly chalconyl-ester core LCs having variable side chain and fixed disubstituted butoxy group at another terminal end. All this compounds were well charac...

Recent technological advances and increasing energy demands have triggered the development and synthesis of novel materials for efficient energy storage and conversion devices in order to cater the energy need of the society. The metal organic frameworks (MOFs), are porous crystalline hybrid materials fashioned by linkage of the metal centers (clusters) and organic linkers (organic ligands), have been recognized as very active research domain due to their broad range of applications as energy storage and conversion materials, regioselective chemical refinements, and petrochemicals for more than the past decade or so. In the current research domain, the emerging MOFs have attracted research community due to their unique properties including tunable porosities, high surface area, modifiable morphologies, layer by layer design and high-quality crystalline product. The present review deals with the state-of-the-art MOFs design, compositions and recent developments and breakthroughs with special reference to the energy conversion and storage device applications such as solar cells, fuel cells, white light emitting diodes, Lithium-ion batteries, Sodium-ion batteries, Zinc-air batteries, Aluminum-air batteries and supercapacitors. The review also highlights various synthesis routes, progress in synthesis of the ultra-high porous MOFs along with the current challenges and future applications of the promising MOF materials.

In Cd-based and CIGS solar cells, the CdS is used as optical window to ensure maximum transmittance of the incident irradiance towards absorber-layer while Cadmium free viable alternative is required to replace toxic CdS layer. Herein, ZnSe films of thickness 200 nm were prepared by electron-beam evaporation followed by annealing in air ambient and vacuum within temperature range 100−300 °C and then subjected to various characterization tools to optimize physical properties for buffer layer applications. The structural properties demonstrate Zinc blende cubic structure with preferred reflection corresponding to (111) plane. The optical properties reveal to high transmittance in visible and nearly IR regions and direct energy band-gap is estimated within 2.53–2.65 eV range. The surface morphology indicates uniform deposition with grain-growth, EDS analysis confirms deposition of films and current-voltage relation indicates ohmic behavior. The findings warrant for applying films air annealed at 300 °C as potential buffer-layer in solar cells.

The Cd-based solar cells possess rear contact problem in superstrate device architecture, which may be eliminated by inserting a suitable buffer layer of zinc telluride (ZnTe) films of appropriate thickness between CdTe absorber and Cu/Au metal contacts. The present work meticulously reports the influence of annealing on the physicochemical properties of ZnTe thin films where ZnTe films were grown employing electron beam thermal evaporation technique and subsequently annealed for 1 h in air ambient and vacuum in 100–300 °C temperature range with an interval of 100 °C. Structural analysis reveals that as-grown and air/vacuum annealed ZnTe films have (111) preferred reflection with zinc blende structure of cubic phase (except 300 °C air annealed films) and grain size is boosted from 22 to 40 nm with annealing. The direct optical energy band gap is estimated in range of 2.25–2.84 eV and 2.65–2.87 eV for air and vacuum annealing, respectively. The contacts between the film surface and the TCO layer showed ohmic behavior as revealed by the I–V characteristics. The EDS results confirmed ZnTe thin film deposition and FESEM micrographs of air annealed films demonstrated the grain growth. The AFM images of vacuum annealed films showed hill-like topographies where hill density and RMS surface roughness reduced with annealing. The findings warrant that 100 °C air annealed ZnTe thin films could be employed as an efficient buffer layer and rear contact material to the Cd-based solar cell devices.

The possibility of maximum transmittance at lower thickness of light transmitting ZnS layer and its optimization by air-annealing as an alternative to hazardous and expensive CdS is reported in this communication in order to achieve better buffer layer for solar cells. Thin films of ZnS were deposited using e-beam evaporation on glass and ITO substrates and subjected to air-annealing followed by characterizations for physical properties. XRD patterns revealed amorphous behavior which transformed into cubic (111) plane with change of substrate and annealing whereas surface topography reveals hill and deep valley like structures. Optimal transmittance of maximum 95% in visible region, direct band gap of 3.38 eV and maximum electrical conductivity were observed for 200 °C annealed films. The study refers that films annealed at 200 °C are claimed to be suitable for buffer layer applications.