01680nas a2200169 4500008004100000245007800041210006900119260000800188300001600196490000700212520111300219100002001332700001801352700002001370700001601390856010401406 2016 eng d00aInfluence of carbon and phosphorus doping on electronic properties of ZnO0 aInfluence of carbon and phosphorus doping on electronic properti cDEC a12318-123220 v273 aZnO is one of the most promising candidate for photoelectrochemical splitting of water for hydrogen production. To increase the efficiency of ZnO based photoelectrochemical cell, its band-gap and band edges should be tailored to match visible light spectra and water redox potential respectively. In this paper, First-principles density functional theory calculations have been performed to evaluate the effect of non-metal dopants on electronic properties of ZnO. The model structures of X-doped ZnO were constructed using 32-atom 2 x 2 x 2 supercell of wurtzite ZnO with one O atom replaced with X (carbon C, phosphorus P). With respect to the electronic band structure, C (2p), P (3p) states are located above the valence band maximum of ZnO and mixing of these states is feeble to produce significant band gap narrowing. Doping of these non-metals dopants helps in the creation of isolated states which enhances visible light absorption of ZnO. Our theoretical calculations are consistent with the experimental results of C (P) doped ZnO and fully explains its visible light activity on non-metal doping.1 aSharma, Vidhika1 aPrasad, Mohit1 aJadkar, Sandesh1 aPal, Sourav uhttps://library.ncl.res.in/content/influence-carbon-and-phosphorus-doping-electronic-properties-zno01701nas a2200229 4500008004100000245012700041210006900168260000800237300001200245490000800257520089500265100001801160700002101178700002001199700002101219700002001240700001801260700002401278700001801302700002001320856013101340 2016 eng d00aWide band gap and conducting tungsten carbide(WC) thin films prepared by hot wire chemical vapor deposition(HW-CVD) method0 aWide band gap and conducting tungsten carbideWC thin films prepa cNOV a315-3170 v1833 a

In this letter, we report synthesis of tungsten carbide (WC) thin films having wide band gap(3.22-3.3 eV) with high electrical conductivity (80-1260 S/cm) by HW-CVD using heated using heated W filament and Tetra-fluoro-methane (CF4) gas. Formation of WC was confirmed by low angle XRD, Raman spectroscopy and x-ray photoelectron spectroscopy. UV-Visible spectroscopy analysis revealed that the synthesized films have high transmission at wavelength 500 nm. Electrical properties measured using Hall measurement show that these films are semiconductor. The obtained results imply that the growth of WC thin films is mainly from the atomic species(W and C) evaporated from the hot filament. The HW-CVD opens a novel route to synthesize wide band gap and conducting WC at a cost-efficient way for DSSCs and hydrogen evolution reaction (HER). (C) 2016 Elsevier B. V. All rights reserved.

1 aPawbake, Amit1 aWaykar, Ravindra1 aJadhavar, Ashok1 aKulkarni, Rupali1 aWaman, Vaishali1 aDate, Abhijit1 aLate, Dattatray, J.1 aPathan, Habib1 aJadkar, Sandesh uhttps://library.ncl.res.in/content/wide-band-gap-and-conducting-tungsten-carbidewc-thin-films-prepared-hot-wire-chemical-vapor01985nas a2200229 4500008004100000245010700041210006900148260000800217300002800225490000800253520119900261100001901460700001801479700002101497700002001518700001801538700002001556700001801576700001901594700002001613856012201633 2017 eng d00aSynthesis of gamma-WO3 thin films by hot wire-CVD and investigation of its humidity sensing properties0 aSynthesis of gammaWO3 thin films by hot wireCVD and investigatio cMAY aArticle Number: 16007170 v2143 aIn this study, monoclinic tungsten oxide (gamma-WO3) have been grown in a single step using HW-CVD method by resistively heating W filaments in a constant O-2 pressure. The formation of gamma-WO3 was confirmed using low angle-XRD and Raman spectroscopy analysis. Low angle-XRD analysis revealed that as-deposited WO3 film are highly crystalline and the crystallites have preferred orientation along the (002) direction. HRTEM analysis and SAED pattern also show the highly crystalline nature of WO3 with d spacing of similar to 0.38 nm, having an orientation along the (002) direction. Surface topography investigated by SEM analysis shows the formation of a uniform and homogeneous cauliflower like morphology throughout the substrate surface without flaws and cracks. A humidity sensing device incorporating WO3 is also fabricated, which shows a maximum humidity sensitivity factor of similar to 3954% along with a response time of similar to 14 s and a recovery time of similar to 25 s. The obtained results demonstrate that it is possible to synthesize WO3 in a single step by HW-CVD method and to fabricate a humidity sensor by using it. (C) 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim1 aJadkar, Vijaya1 aPawbake, Amit1 aWaykar, Ravindra1 aJadhavar, Ashok1 aDate, Abhijit1 aLate, Dattatray1 aPathan, Habib1 aGosavi, Suresh1 aJadkar, Sandesh uhttps://library.ncl.res.in/content/synthesis-gamma-wo3-thin-films-hot-wire-cvd-and-investigation-its-humidity-sensing02312nas a2200265 4500008004100000245012900041210006900170260000800239300001600247490000700263520139200270100001601662700002001678700002101698700001801719700002101737700002401758700002001782700002401802700002601826700002401852700001901876700002001895856013101915 2018 eng d00aHydrothermal synthesis of rGO-PbBi2Se4 composite and investigation of its structural, chemical and field emission properties0 aHydrothermal synthesis of rGOPbBi2Se4 composite and investigatio cJUN a10494-105030 v293 aIn the present study we report the one step facile synthesis of pristine lead bismuth selenide (PbBi2Se4) and reduced graphene oxide (rGO) and its composites with PbBi2Se4. Formation of pristine PbBi2Se4 and rGO-PbBi2Se4 composite were confirmed by X-ray diffraction and X-ray photoelectron spectroscopy. The surface morphology and topography investigated by using scanning electron microscopy and transmission electron microscopy revealed the formation of nano-flowers pristine PbBi2Se4. After coupling pristine PbBi2Se4 with rGO the surface morphology shows the formation of sharp vertically protruded nano-sheets/nano-flaks originated from the nano-flowers. Finally, the field emission properties of pristine PbBi2Se4 and rGO-PbBi2Se4 composite have been investigated. It has been observed that the rGO-PbBi2Se4 composite emitter exhibited excellent field emission properties with low turn-on field (similar to 2.8 V/A mu m for 10 A mu A/cm(2)), high emission current density (similar to 1288 A mu A/cm(2) at 3.9 V/A mu m) and superior current stability (similar to 4.5 h for similar to 1 A mu A) compare to pristine PbBi2Se4 emitter. Thus, the facile one step synthesis approach and robust nature of rGO-PbBi2Se4 composite emitter can provide prospects for the future development of large-area emitter applications such as flat-panel-display and vacuum micro/nanoelectronics devices.1 aAher, Rahul1 aBhorde, Ajinkya1 aSharma, Priyanka1 aNair, Shruthi1 aBorate, Haribhau1 aPandharkar, Subhash1 aRondiya, Sachin1 aChaudhary, Minakshi1 aGopinath, Chinnakonda1 aSuryawanshi, Sachin1 aMore, Mahendra1 aJadkar, Sandesh uhttps://library.ncl.res.in/content/hydrothermal-synthesis-rgo-pbbi2se4-composite-and-investigation-its-structural-chemical-and02586nas a2200325 4500008004100000022001400041245011200055210006900167260000800236300001200244490000800256520159300264653002001857653001301877653001801890653000801908653000801916100001601924700002001940700001801960700002101978700002401999700001902023700001902042700001702061700002002078700001802098700002002116856012402136 2019 eng d a1862-630000aSolvothermal growth of PbBi2Se4 nano-flowers: a material for humidity sensor and photodetector applications0 aSolvothermal growth of PbBi2Se4 nanoflowers a material for humid cJUN a19000650 v2163 a

In the present work, lead bismuth selenide (PbBi2Se4) nano-flowers are synthesized by using a simple solvothermal method. Humidity sensor and photodetector based on PbBi2Se4 nano-flowers are fabricated on indium tin oxide (ITO) substrates and their sensing properties are investigated. Formation of PbBi2Se4 is confirmed by XRD, EDS, and XPS whereas formation of nano-flowers is confirmed by SEM and TEM analysis. XRD analysis reveals the hexagonal crystal structure of PbBi2Se4 phase with a = b = 4.22 angstrom, and c= 17.42 angstrom. The surface morphology of PbBi2Se4 clearly shows the formation of well-organized flower-like nanostructures which closely resembles the shape of Dahlia. The elemental mapping of chemical constituents obtained from SEM-EDS analysis shows uniform distribution of chemical constituents for the Pb, Bi, and Se in PbBi2Se4 nano-flowers. The PbBi2Se4 nano-flowers based humidity sensor has a typical response time of approximate to 65s and recovery time of approximate to 75 s. In case of PbBi2Se4 nano-flowers-based photodetector, the response and recovery time are observed approximate to 121 and approximate to 123 s, respectively, under visible light illumination with photoresponsivity (5 x 10(-6)), photosensitivity (2.16%), and quantum efficiency (1.5 x 10(4)). The obtained results demonstrate the potential applications of solvothermally grown PbBi2Se4 nano-flowers-based devices for humidity sensors and photodetectors. The ease of the present work is to develop novel material to obtain device quality humidity sensors and photodetectors.

10ahumidity sensor10aPbBi2Se410aphotodetector10aXPS10aXRD1 aAher, Rahul1 aBhorde, Ajinkya1 aNair, Shruthi1 aBorate, Haribhau1 aPandharkar, Subhash1 aNaik, Dhirsing1 aVairale, Priti1 aKarpe, Smita1 aLate, Dattatray1 aPrasad, Mohit1 aJadkar, Sandesh uhttps://library.ncl.res.in/content/solvothermal-growth-pbbi2se4-nano-flowers-material-humidity-sensor-and-photodetector02758nas a2200241 4500008004100000022001400041245014000055210006900195260000800264300001400272490000700286520189900293100002002192700002202212700002002234700001902254700001602273700003202289700002302321700002202344700002002366856013002386 2023 eng d a0020-166900aLead-free solid state mechanochemical synthesis of Cs2NaBi1-XFeXCl6 double perovskite: reduces band gap and enhances optical properties0 aLeadfree solid state mechanochemical synthesis of Cs2NaBi1XFeXCl cMAR a4861-48710 v623 a

Efficient and stable lead-free halide double perovskites (DPs) have attracted great attention for the future generation of electronic devices. Herein, we have developed a doping approach to incorporate Fe3+ ions into the Cs2NaBiCl6 crystal unit and reveal a crystallographic and optoelectronic study of the Cs2NaBi1-xFexCl6 double perovskite. We report a simple solid-state mechanochemical method that has a solvent-free, one-step, green chemistry approach for the synthesis of Cs2NaBi1-xFexCl6 phosphor. The analysis of powder X-ray diffraction (XRD) data determines the contraction of the lattice due to the incorporation of Fe3+ cations, and this effect is well supported by X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), Raman spectroscopy, and solid-state nuclear magnetic resonance spectroscopy (ss-NMR). The band gap is reduced with increasing Fe content owing to the strong overlap of the Fe-3d orbitals with Cl-3p orbitals and shift of the valence band maxima (VBM) toward higher energies, as confirmed by ultraviolet photoelectron spectroscopy (UPS) and density functional theory (DFT) analyses. Photoluminescence (PL) studies of Cs2NaBi1-xFexCl6 phosphors exhibit a large Stokes shift, broadband emission, and increased PL intensity more than ten times for 15% of Fe content phosphor with enhancement in the average decay lifetimes (up to 38 ns) compared to pristine Cs2NaBiCl6 DP. These results indicate that the transition of dark self-trapping of excitons (STEs) into bright STEs enhances yellow emission. XRD, UV, and thermo-gravimetric analysis (TGA) confirmed that the Cs2NaB1-xFexCl6 DPs have good structural and thermal stabilities. Our findings indicate that the doping of Fe3+ cations into the Cs2NaBiCl6 lattice is a constructive strategy to enhance significantly the optoelectronic properties of these phosphors.

1 aUdavant, Rohini1 aThawarkar, Sachin1 aRondiya, Sachin1 aShelke, Ankita1 aAher, Rahul1 aAjithkumar, Thalasseril, G.1 aCross, Russell, W.1 aDzade, Nelson, Y.1 aJadkar, Sandesh uhttps://library.ncl.res.in/content/lead-free-solid-state-mechanochemical-synthesis-cs2nabi1-xfexcl6-double-perovskite-reduces