American Journal of Materials Science最新文献

{"title":"P3HT:PCBM/TiOx Interface Modification through Annealing for Improvement in Organic Solar Cell Performance","authors":"Sanjay S. Ghosh, Ganesh S. Lonakar, Mrunal S. Mahajan, S. Jadkar, J. Sali","doi":"10.7726/AJMST.2013.1010-1","DOIUrl":"https://doi.org/10.7726/AJMST.2013.1010-1","url":null,"abstract":"We describe the study of annealing after coating a TiOx film over P3HT:PCBM bulk heterojunction layer to improve the interface in order to improve the solar cell performance. We demonstrate that annealing after coating the TiOx interfacial film improves the interface between the bulk-heterojunction and TiOx layers and hence the device performance. However upon annealing the devices before coating the TiOx layer results in highly degraded performance. A systematic explanation of the improved device performance is","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":"2106 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91351932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural, Magnetic and Electronic Properties of ErN in Three Structural Phases: First Principal Calculations","authors":"S. Dergal, A. Merad, B. N. Brahmi","doi":"10.7726/AJMST.2013.1005","DOIUrl":"https://doi.org/10.7726/AJMST.2013.1005","url":null,"abstract":"Structural, magnetic and electronic properties of the Erbium nitride (ErN) compound were studied by first-principles FP-LAPW calculations within SIC-PBE-sol+ U (the generalized gradient approximation GGA of PBE developed for solids with the self-interaction corrected (SIC) and addition of Hubbard U corrections). Three possible potential structures were considered: known phases, NaCl and CsCl, and an unknown phase, ZnS. Our results show that ErN is a ferromagnet (FM) in all studied phases. Our calculations of electronic properties showed for both NaCl and CsCl phases a metal behavior for spin up and spin down, and for ZnS phase, a semiconductor (metal) behavior for spin up (spin down) (2.1eV) respectively. To our knowledge, there is no data for comparison in ZnS structure; therefore we consider our results as predictions.","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82685229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hole Dangling Bond Capture Cross-Sections in a-Si:H","authors":"D. Goldie","doi":"10.5923/J.MATERIALS.20130304.02","DOIUrl":"https://doi.org/10.5923/J.MATERIALS.20130304.02","url":null,"abstract":"It is demonstrated that the occupation statistics for a Gaussian distribution of dangling bond states may account for the measured variation of hole mob ility-lifetime values in hydrogenated amorphous silicon as the Fermi energy is systematically varied by doping fro m about 0.55 eV to 1.05 eV belo w the conduction band edge. An assessment of how the deduced dangling bond parameters may be influenced by underlying doping effects suggests that the min imu m cross-section ratio for hole capture into charged (σh - ) and neutral (σh 0 ) dangling bond states requires that σh - /σh 0 ≥ 5. The capture of holes is consequently dominated by charged dangling bonds provided the Fermi energy lies within the upper half of the band-gap. Both σh - and σh 0 are observed to depend upon temperature (T) as σh ∝ T -β wh ich may indicate the presence of tunnelling","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":"258 1","pages":"70-76"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84642560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Use of Nonionic Tween-80 Surfactant Mobile Phase in Thin Layer Chromatography of Heavy Metal Cations","authors":"Sarang S. Dhote, L. Deshmukh, L. Paliwal","doi":"10.7726/AJMST.2013.1002","DOIUrl":"https://doi.org/10.7726/AJMST.2013.1002","url":null,"abstract":"The analytical potential of Tween-80, a nonionic surfactant used as a mobile phase in the thin layer chromatographic separation of heavy metal cations, is assessed. The surfactant concentrations, acidity and basicity of Tween-80solutions are investigated for the migration behavior of heavy metal cations on aminoplast+ cellulose mixture thin layer. The influence of weak or strong electrolyte and alkanol additives in the surfactant-containing mobile phase on the mobility of heavy metal cations on the aminoplast+ cellulose mixture thin layer is examined.","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78229999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis and Characterization of Magnesium Perchlorate Doped Polyaniline- PVC Films","authors":"G. Rani, H. Kumar, Renu Rani","doi":"10.7726/AJMST.2013.1006","DOIUrl":"https://doi.org/10.7726/AJMST.2013.1006","url":null,"abstract":"Spectroscopic characterization explores the possibility of potential applications of organic conducting polymers in electronic device fabrication. In this work FTIR and SEM (Scanning Electron Microscopy) techniques are used for characterization of the prepared conducting polyaniline PVC films by changing the concentration of dopant. FTIR study indicates the presence of injected charge species that may lead the possibility of existence of both singlet and triplet excitation states. These types of measurements of [Mg (ClO4)2] doped Polyaniline system will be helpful for preparing polyaniline-PVC blend/conducting polymeric materials.","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88024885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphology and Optical Properties of Template Synthesized Copper-Telluride Nanowires","authors":"Suresh Kumar, V. Singh, A. Vohra, S. Chakarvarti","doi":"10.7726/AJMST.2013.1009","DOIUrl":"https://doi.org/10.7726/AJMST.2013.1009","url":null,"abstract":"Copper tellurides (CuxTe) are important class of materials suitable for use as active components in CdTe based solar cells. Among all these wide band gap materials, copper telluride is a very important material for wide range of applications. Copper tellurides (CuxTe) have different crystal structures depending upon the value of x (1<x<2) and are usually p-type compound semiconductors. Copper tellurides (CuxTe) are widely used as back-contact materials to CdS/CdTe photovoltaic devices for higher efficiency and stability of the device.Cu2Te/n-CdTe hetero-junction solar cells have been reported with an efficiency reaching 7.5%. We report here the morphological and optical properties of template synthesized copper-telluride nanowires. The copper tellurides (CuxTe) nanowires were synthesized on copper and ITO-coated glass (with ITO thickness of 1500A and resistivity of 15-20 Ohm-cm) substrates via template-assisted (polycarbonate tracketch membrane) electrodeposition technique at room temperature (303K). The morphologies of copper telluride nanowires were studied by scanning electron microscopy which reveals the uniform growth of standing nanowires of identical diameter equal to the diameter of the template used. The electrodeposited nanowires are found to be highly ordered, vertically aligned and of high aspect ratio. To investigate the optical properties of as-synthesized copper telluride nanowires, we performed UV-Vis measurements at room temperature (303K). It is found from the absorption spectra that the optical absorption edge moves to shorter wavelength region with decrease in diameter. The band gap energy is found to be 2.78, 3.10 and 3.37eV for 200, 100 and 50nm copper telluride nanowires, respectively. The change in the band gap with diameter shows the “blue shift” in copper telluride nanowires which can be attributed to the quantum size effect in nanowires. We found broad PL emission spectra of 200, 100 and 50nm copper telluride nanowires and photoluminescence emission peak at around 456nm in the blue region (450-475nm) with excitation wavelength of 220nm were observed. The other emission peak at around 555nm is also observed in all copper telluride nanowires respectively which attributed to the green emission in the visible region.","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73951043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photophysical Properties of Eosin Y in Aqueous Glycol Oligomer Mixtures","authors":"B. Ganguly, R. K. Nath","doi":"10.7726/AJMST.2013.1004","DOIUrl":"https://doi.org/10.7726/AJMST.2013.1004","url":null,"abstract":"","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87394617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adjusted Adashi's Model of Exciton Bohr Parameter and New Proposed Models for Optical Properties of III-V Semiconductors","authors":"Nawal Korti-Baghdadli, A. Merad, T. Benouaz","doi":"10.7726/AJMST.2013.1008","DOIUrl":"https://doi.org/10.7726/AJMST.2013.1008","url":null,"abstract":"The energy gap of the semiconductor changes dramatically with its size. Consequently the determination of the correlation between the exciton Bohr parameter (aB), which is a size parameter, and the energy gap (Eg) is a main property for understanding the behaviour of the nanostructure properties. In this work, we propose the adjustment of Adashi’s model of exciton Bohr parameter with energy band gap to III-V family of semiconductors and propose new numerical models linking the exciton Bohr parameter (aB) to the optical properties such as the refractive index (n) and the dielectric constant (e). We found that our predictions will be more accurate for this family of semiconductors. Our objective is to propose some models which corresponding to bulk semiconductors and giving predictions to semiconductor nanostructures.","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78564395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Growth and Characterization of Electrospun LaMnO3 Nanofibers by Electrospinning Technique","authors":"Y. Maung, Zin Min Myat, T. Win, K. Soe","doi":"10.7726/AJMST.2013.1003","DOIUrl":"https://doi.org/10.7726/AJMST.2013.1003","url":null,"abstract":"The polycrystalline perovskite structure of LaMnO3 nanofibers was obtained by calcination of the PVA/[LaCl3+MnCl2+(NH4)2CO3] composite at 600°C with electrospinning technique. The decomposition and crystalline behavior of sample were examined by Thermogravimetric and Simultaneous Differential Thermal Analysis (TG-DTA). The crystal structure and phase formation were characterized by X-ray Diffraction (XRD). Scanning Electron Microscopy (SEM) was performed and the diameters of the LaMnO3 nanofibers were calculated to be 42 nm and 55 nm with different spinning intervals at 600°C. SEM analysis was also carried out to examine the fiber diameters and morphological properties.","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83157544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative Studies of The Effect of Particle Size on the Microstructural Characteristics of Bi 2 O 3 and Sb 2 O 3 Additives on Sintered Zno Ceramics","authors":"S. C. Udensi","doi":"10.5923/J.MATERIALS.20120205.04","DOIUrl":"https://doi.org/10.5923/J.MATERIALS.20120205.04","url":null,"abstract":"Two different powder samples of ZnO with minuscule additives, of Bi2O3 and Sb2O3 were prepared through ball milling, in solutions containing deionized water and polyvinyl alcohol (PVA ) using zirconia balls. The powder samples were sieved to obtain particle size ranges of ≤ 38μm (Z, ZB, ZBS) and ≤ 63μm (Z 1, ZB1, ZBS1). The sample pellets were sintered at 800℃/ 60mins and 1100℃/600mins and their microstructures examined using SEM and X-ray for densification and coarsening kinetics. Grain growths were observed for samples ZB and ZB1 at both temperatures due to the format ion of bismuth-rich liquid phase, whereas for ZBS and ZBS1 grains growths were hindered because of the enclosure of spinel phase which pinned grain boundary motion. SEM micrographs show high densities for particle size range of ≤ 38μm at both temperatures, while for particle size range of ≤ 63μm, densificat ion was highest at 1100℃/ 600mins.The decisive parameters which controlled densification were found to be temperature, sintering time and particle geometry. In the cases where all three parameters were utilized (Z, ZB, ZBS at 1100℃/600mins), denser materials were obtained. Also equal masses of representative samples of ZB and ZB1 were seen to be electrically co mparable fro m the nonlinear p lot.","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":"3 1","pages":"153-159"},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85469778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}