High performance photodiodes based on chemically processed Cu doped SnS₂ nanoflakes

Mohan Kumar, G.,Xiao, Fu,Ilanchezhiyan, P.,Yuldashev, Sh.,Madhan Kumar, A.,Cho, H.D.,Lee, D.J.,Kang, T.W. Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.455 No.-

<P><B>Abstract</B></P> <P>In this work, Cu doped SnS<SUB>2</SUB> nanoflakes were synthesized through a simple hydrothermal method. The influence of Cu doping on the structural, optical and electrical properties of SnS<SUB>2</SUB> were investigated in detail. Optical properties explores the Cu doping in SnS<SUB>2</SUB> crystal lattice to result with a red-shift in absorption spectrum, which benefits visible-light absorption. Photodiodes were further fabricated by spin coating Cu doped SnS<SUB>2</SUB> nanoflakes on p-type silicon (Si). Electrical and photoelectrical parameters of Cu doped SnS<SUB>2</SUB> nanoflakes were determined by studying their impedance and current–voltage (I–V) characteristics, respectively. The diodes were found to exhibit excellent rectifying behavior and good sensitivity on par to pristine photodiodes. Impedance results identified the resistance of device to reduce considerably on Cu doping. The enhanced photoelectrical properties of the heterojunctions has been ascribed to Cu ions, which act as effective dopant and contribute to the varied carrier concentration in SnS<SUB>2</SUB>. Finally the obtained results suggest the potential of Cu-doped SnS<SUB>2</SUB> for application in photodetection and sensors applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cu doped SnS<SUB>2</SUB> nanoflakes were synthesized in hexagonal phase. </LI> <LI> Nature of charge carriers/carrier density was determined using Mott-Schottky plots. </LI> <LI> Photodiode based on Cu doped SnS<SUB>2</SUB> nanoflakes were fabricated on p-Si substrate. </LI> <LI> Photodiode revealed improved photocurrent and responsitivity values under illumination. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Report of the CCQM-K97: measurement of arsenobetaine standard solution and arsenobetaine content in fish tissue (tunafish)

Ma, L D,Wang, J,WEI, C,Kuroiwa, T,Narukawa, T,Ito, N,HIOKI, A,CHIBA, K,Yim, Y H,Lee, K S,Lim, Y R,Turk, G C,Davis, C W,Mester, Z,Yang, L,McCooeye, M,Maxwell, P,Cankur, O,Tokman, N,Coskun, F G BUREAU INTERNATIONAL DES POIDS ET MESURES 2017 METROLOGIA -BERLIN- Vol.54 No.-

<P></P> <P>The CCQM-K97 key comparison was organized by the inorganic analysis working group (IAWG) of CCQM as a follow-up to completed pilot study CCQM-P96 and P96.1 to test the abilities of the national metrology institutes to accurately quantitate the mass fraction of arsenobetaine (AsB) in standard solution and in fish tissue. A pilot study CCQM-P133 was parallelized with this key comparison. National Institute of Metrology (NIM), China and National Metrology Institute of Japan (NMIJ) acted as the coordinating laboratories.</P> <P>Six NMIs participated in CCQM-K97 and two institutes participated in CCQM-P133, and all of them submitted the results. Some NMIs submitted more than one results by different methods. The results were in excellent agreement with each other, and obviously better than those of previous P96 and P96.1. Therefore the calibrant which each NMI used was comparable. It shows that the capabilities of some of the participants have been improved after the previous pilot studies.</P> <H2>Main text</H2> <P> To reach the main text of this paper, click on <A HREF='http://www.bipm.org/utils/common/pdf/final_reports/QM/K97/CCQM-K97.pdf'>Final Report</A>. Note that this text is that which appears in Appendix B of the BIPM key comparison database <A HREF='http://kcdb.bipm.org/'>kcdb.bipm.org/</A>.</P> <P>The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).</P>

Toward high efficiency organic photovoltaic devices with enhanced thermal stability utilizing P3HT-b-P3PHT block copolymer additives

Zhu, M.,Kim, H.,Jang, Y.,Park, S.,Ryu, D.,Kim, K.,Tang, P.,Qiu, F.,Kim, D.,Peng, J. Royal Society of Chemistry 2016 Journal of Materials Chemistry A Vol.4 No.47

<P>Organic photovoltaics (OPVs) have drawn an extensive amount of attention due to their low cost, processibility and flexibility. However, a cell based on a blend of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C-61-butyric acid methyl ester (PC61BM) has a limited power conversion efficiency (PCE) due to the short exciton diffusion length of similar to 10 nm. We address this issue by designing a series of all-conjugated diblock copolymers, poly(3-hexylthiophene)-b-poly(3-(6-diethylphosphonatohexyl) thiophene) (P3HT-b-P3PHT), intended for use as additives to improve the performance of P3HT:PC61BM-based photovoltaic devices. The PCE of the devices improved from 3.30% to 4.03% with the addition of P3HT-b-P3PHT (3 : 1). The thermal stability of devices with P3HT-b-P3PHT additives improved significantly relative to that of the P3HT:PC61BM reference device, where the devices including a copolymer with a higher P3PHT content exhibited a better thermal stability. It was found that the fill factor (FF) could be regulated by simply varying the block ratio of P3HT-b-P3PHT and played a crucial role in improving both the PCE and the thermal stability. The P3HT-b-P3PHT diffused at the P3HT:PC61BM interface, improved the miscibility between P3HT and PC61BM, optimized the nanoscale morphology of the photoactive layer, and reduced the active layer roughness, all of which improved the FF and thus contributed to an improvement in device performance.</P>

Photoswitching and photocatalytic functions of Sn_xCu_1−xS nanostructures

Ilanchezhiyan, P.,Kumar, G. Mohan,Siva, C.,Venkatasubbu, G. Devanand,Kang, T.W.,Kim, D.Y. Elsevier 2019 APPLIED SURFACE SCIENCE - Vol.489 No.-

<P><B>Abstract</B></P> <P>Ultra-thin semiconducting nanostructures are garnering strategic importance in energy and environment remediation applications. In this regard, Sn<SUB>x</SUB>Cu<SUB>1−x</SUB>S nanostructures were processed through an eco-friendly chemical route and investigated in detail for photoswitching and photocatalytic functions. X-ray diffraction, FT-IR, Raman, UV–vis absorbance and high-resolution microscopic tools were initially used to examine the physico-chemical traits of Sn<SUB>x</SUB>Cu<SUB>1−x</SUB>S nanostructures. Ambiguous evidence for the substitution of Sn ions in place of Cu ions was attained through X-ray photoelectron spectroscopy. The photocatalytic performance of Sn<SUB>x</SUB>Cu<SUB>1−x</SUB>S systems was investigated through effective remediation of organic dye molecules under visible light. Scavenger based photocatalytic experiments were additionally carried out to infer the degradation mechanism. Type II <I>p-n</I> Sn<SUB>x</SUB>Cu<SUB>1−x</SUB>S/In<SUB>2</SUB>S<SUB>3</SUB> heterojunction diodes were also demonstrated for the first time with improved electrical conductivity and photoelectrical performances. The rectification ratio, forward current values and photo switching capabilities of these diodes were noted to improve in the Current vs. Voltage (I-V) and Current vs. Time (I-T) curves as a function of Sn composition and applied bias potential. The excellent photo switching stability augments the photo generated carriers to be effectively separated along the p-n junctions. The enhanced photoelectronic and photocatalytic functionalities in Sn<SUB>x</SUB>Cu<SUB>1−x</SUB>S has finally been reasoned to the improved charge transfer kinetics in the respective architectures, resulting from the effective Sn interaction in hexagonal host lattice.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Sn<SUB>x</SUB>Cu<SUB>1−x</SUB>S nanostructures were fabricated by hydrothermal route. </LI> <LI> The nanostructures exhibited excellent photocatalytic activity under visible light. </LI> <LI> Sn interaction in hexagonal host lattice promoted their photocatalytic performance. </LI> <LI> p-Sn<SUB>x</SUB>Cu<SUB>1−x</SUB>S/n-In<SUB>2</SUB>S<SUB>3</SUB> diodes demonstrated improved photoswitching performance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Balanced intake of protein and carbohydrate maximizes lifetime reproductive success in the mealworm beetle, Tenebrio molitor (Coleoptera: Tenebrionidae)

Rho, M.S.,Lee, K.P. Pergamon Press 2016 Journal of insect physiology Vol.91 No.-

<P>Recent developments in insect gerontological and nutritional research have suggested that the dietary protein:carbohydrate (P:C) balance is a critical determinant of lifespan and reproduction in many insects. However, most studies investigating this important role of dietary P:C balance have been conducted using dipteran and orthopteran species. In this study, we used the mealworm beetles, Tenebrio molitor L. (Coleoptera: Tenebrionidae), to test the effects of dietary P:C balance on lifespan and reproduction. Regardless of their reproductive status, both male and female beetles had the shortest lifespan at the protein-biased ratio of P:C 5:1. Mean lifespan was the longest at P:C 1:1 for males and at both P:C 1:1 and 1:5 for females. Mating significantly curtailed the lifespan of both males and females, indicating the survival cost of mating. Age-specific egg laying was significantly higher at P:C 1:1 than at the two imbalanced P:C ratios (1:5 or 5:1) at any given age throughout their lives, resulting in the highest lifetime reproductive success at P:C 1:1. When given a choice, beetles actively regulated their intake of protein and carbohydrate to a slightly carbohydrate-biased ratio (P:C 1:1.54-1:1.64 for males and P:C 1:1.31:1.36 for females). The self-selected P:C ratio was significantly higher for females than males, reflecting a higher protein requirement for egg production. Collectively, our results add to a growing body of evidence suggesting the key role played by dietary macronutrient balance in shaping lifespan and reproduction in insects. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Expression phenotype changes of EBV-transformed lymphoblastoid cell lines during long-term subculture and its clinical significance

Lee, J.-E.,Nam, H.-Y.,Shim, S.-M.,Bae, G.-R.,Han, B.-G.,Jeon, J.-P. Blackwell Publishing Ltd 2010 Cell proliferation Vol.43 No.4

<P>Abstract</P><P>Objectives: </P><P>The EBV-transformed lymphoblastoid cell line (LCL) is a useful resource for population-based human genetic and pharmacogenetic studies. The principal objective here was to assess expression phenotype changes during long-term subculture of LCLs, and its clinical significance.</P><P>Materials and methods: </P><P>We searched for genes that were differentially expressed in 17 LCLs at late (p161) passage compared to early passage (p4) using microarray assay, then validated them by real-time RT-PCR analysis. In addition, we estimated correlations between expression phenotypes of 20 LCL strains at early passage and 23 quantitative clinical traits from blood donors of particular LCL strains.</P><P>Results: </P><P>Transcript sequences of 16 genes including nuclear factor-&kgr;B (NF-&kgr;B) pathway-related genes (such as <I>PTPN13</I>, <I>HERC5</I> and miR-146a) and carcinogenesis-related genes (such as <I>XAF1</I>, <I>TCL1A</I>, <I>PTPN13</I>, <I>CD38</I> and miR-146a) were differentially expressed (>2-fold change) in at least 15 of the 17 LCL strains. In particular, <I>TC2N</I>, <I>FCRL5</I>, <I>CD180</I>, <I>CD38</I> and miR-146a were downregulated in all 17 of the evaluated LCL strains. In addition, we identified clinical trait-associated expression phenotypes in LCLs.</P><P>Conclusion: </P><P>Our results showed that LCLs acquired expression phenotype changes involving expression of NF-&kgr;B pathway- and carcinogenesis-related genes during long-term subculture. These differentially expressed genes can be considered to be a gene signature of LCL immortalization or EBV-induced carcinogenesis. Clinical trait-associated expression phenotypes should prove useful in the discovery of new candidate genes for particular traits.</P>

Unraveling the Atomistic Sodiation Mechanism of Black Phosphorus for Sodium Ion Batteries by First-Principles Calculations

Hembram, K. P. S. S.,Jung, Hyun,Yeo, Byung Chul,Pai, Sung Jin,Kim, Seungchul,Lee, Kwang-Ryeol,Han, Sang Soo American Chemical Society 2015 The Journal of Physical Chemistry Part C Vol.119 No.27

<P>As opposed to the standard graphite anode used for lithium (Li) ion batteries (LIBs), a standard anode material for sodium (Na) ion batteries (NIBs) has not yet been reported. Black phosphorus is potentially very attractive as an anode material for NIBs, as it has a layered structure similar to graphite but a greater interlayer distance. In this work, we propose an atomistic mechanism for the sodiation of black phosphorus, based on first-principles calculations. The layered structure of black phosphorus is maintained up to the composition of Na<SUB>0.25</SUB>P, with <I>one-dimensional</I> sodiation (an intercalation process) occurring in the interlayer spaces of the black phosphorus, resulting in sliding of the phosphorene layers because one Na atom tends to bind to four P atoms. At Na levels beyond Na<SUB>0.25</SUB>P, the intercalation process changes to an alloying process. Sodiation exceeding the critical composition leads to breaking of P–P bonds and eventual formation of an amorphous phase from the layered Na<SUB><I>x</I></SUB>P structure. After the P–P bonds in the layered Na<SUB><I>x</I></SUB>P structure are broken, in a progress in which staggered P–P bonds are preferentially broken rather than planar P–P bonds, P<SUB>2</SUB> dumbbells are generated. As sodiation proceeds further, most of the P<SUB>2</SUB> dumbbells become isolated P atoms. Thus, in the amorphous Na<SUB>3</SUB>P phase, only low-coordinate P components such as isolated atoms (primarily) and dumbbells are found. We expect that our comprehensive understanding of the sodiation mechanism in black phosphorus will provide helpful guidelines in designing new types of black phosphorus anodes to obtain better performing NIBs.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2015/jpccck.2015.119.issue-27/acs.jpcc.5b05482/production/images/medium/jp-2015-054822_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp5b05482'>ACS Electronic Supporting Info</A></P>

Determination of N* amplitudes from associated strangeness production in p+p collisions

Mü,nzer, R.,Fabbietti, L.,Epple, E.,Lu, S.,Klose, P.,Hauenstein, F.,Herrmann, N.,Grzonka, D.,Leifels, Y.,Maggiora, M.,Pleiner, D.,Ramstein, B.,Ritman, J.,Roderburg, E.,Salabura, P.,Sarantsev, A.,B North-Holland Pub. Co 2018 Physics letters. Section B Vol.785 No.-

<P><B>Abstract</B></P> <P>We present the first determination of the energy-dependent amplitudes of N<SUP>⁎</SUP> resonances extracted from their decay in KΛ pairs in p+p → <SUP> pK + </SUP> Λ reactions. A combined Partial Wave Analysis of seven data samples with exclusively reconstructed p+p → <SUP> pK + </SUP> Λ events measured by the COSY-TOF, DISTO, FOPI and HADES Collaborations in fixed target experiments at kinetic energies between 2.14 to 3.5 GeV is used to determine the amplitude of the resonant and non-resonant contributions into the associated strangeness final state. The contribution of seven N<SUP>⁎</SUP> resonances with masses between 1650 MeV/c<SUP>2</SUP> and 1900 MeV/c<SUP>2</SUP> for an excess energy between 0 and 600 MeV has been considered. The Σ–p cusp and final state interactions for the p–Λ channel are also included as coherent contributions in the PWA. The N<SUP>⁎</SUP> contribution is found to be dominant with respect to the phase space emission of the pK Λ + final state at all energies demonstrating the important role played by both N<SUP>⁎</SUP> and interference effects in hadron–hadron collisions.</P>

Influence of flowrates to a reverse electro-dialysis (RED) stack on performance and electrochemistry of a microbial reverse electrodialysis cell (MRC)

Kang, Heunggu,Kim, Eojin,Jung, Sokhee P. Elsevier 2017 International journal of hydrogen energy Vol.42 No.45

<P><B>Abstract</B></P> <P>An MRC is a bioelectrochemical system combining a microbial fuel cell (MFC) with a RED stack to generate electricity from salinity gradient and organic wastewater with simultaneous treatment. Operating an MRC at an optimum flowrate to RED is important because it is closely related with energy production rate and economic feasibility. However, influence of RED flowrates on MRC electrochemistry and power production have not been investigated. For this purpose, four different flowrates of high concentration and low concentration solutions were tested. Maximum power density was highest in 10 mL/min (3.71 W/m<SUP>2</SUP>) and optimum current density was highest in 7.5 mL/min (5.36 A/m<SUP>2</SUP>). By mere increasing the flowrate to MRC, maximum power and optimum current densities increased by 17.7% and 16.2%. EIS showed that impedances of anode, cathode and full-cell were decreased by 51%, 31% and 19%, respectively. Anode CV showed that peak current density was increased by 25.7%. COD removal and CE were not affected by RED flowrate. Power generation at 7.5 mL/min and 10 mL/min were not so different, but current production was better at 7.5 mL/min. Therefore, considering energy production, the RED flowrate of 7.5 mL/min is a reasonable choice for MRC operation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> By increasing RED flowrate, P<SUB>max</SUB> increased by 17.7%. </LI> <LI> By increasing RED flowrate, I<SUB>opt</SUB> increased by 16.2%. </LI> <LI> P<SUB>max</SUB> were similar in 7.7 mL/min and 10 mL/min (∼3.7 W/m<SUP>2</SUP>). </LI> <LI> I<SUB>opt</SUB> was highest in 7.5 mL/min (∼5.4 A/m<SUP>2</SUP>). </LI> <LI> 7.5 mL/min was the best flowrate in the tested MRC. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Chemodosimeter functionalized diatomaceous earth particles for visual detection and removal of trace mercury ions from water

Patil, Pravin,Madhuprasad, Pravin,Bhat, Mahesh P.,Gatti, Manasa G.,Kabiri, Shervin,Altalhi, Tariq,Jung, Ho-Young,Losic, Dusan,Kurkuri, Mahaveer Elsevier 2017 Chemical engineering journal Vol.327 No.-

<P><B>Abstract</B></P> <P>The rhodamine based receptor, P2 has been developed for the detection of environmentally hazardous Hg<SUP>2+</SUP> ions with a limit of detection, 1.5×10<SUP>−6</SUP> M. The P2 showed a significant colour change from colourless to pink upon binding with Hg<SUP>2+</SUP> ions. As a result, a new peak at 533nm was observed in UV–vis spectroscopy which was attributed to spirolactum ring opening followed by through bond energy transfer (TBET). In addition, the presence of other competing cations did not interfere the detection of Hg<SUP>2+</SUP> ions. Further, P2 has been successfully immobilized onto the naturally available and highly porous diatomaceous earth particles (P2D) for removal of Hg<SUP>2+</SUP> ions from water. The covalently attached organic molecule in P2D forms complex with Hg<SUP>2+</SUP> ion present in the water and thus traps the Hg<SUP>2+</SUP> ions. Based on this, a proof-of-concept cartridge has been developed for water purification. The cartridge having 450mg of P2D was able to purify 30mL of water containing 1ppm Hg<SUP>2+</SUP> ions. The efficiency of cartridge could be visualized with a colour change from colourless to pink.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Detection and removal of Hg<SUP>2+</SUP> from water using chemodosimeter P2 were realized. </LI> <LI> P2 has been successfully immobilized onto naturally available diatoms (P2D). </LI> <LI> Organic receptor and hazardous Hg<SUP>2+</SUP> ions were physically contained in diatoms. </LI> <LI> Eco-friendly cartridge containing P2D was developed for the removal of Hg<SUP>2+</SUP> ions. </LI> <LI> Device efficiency (time to replace) could be realized through visual colour change. </LI> </UL> </P>