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A. F. Da Cunha - One of the best experts on this subject based on the ideXlab platform.
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A study of ternary Cu2SnS3 and Cu3SnS4 thin films prepared by sulfurizing stacked metal precursors
Journal of Physics D: Applied Physics, 2010Co-Authors: P. A. Fernandes, P. M. P. Salomé, A. F. Da CunhaAbstract:Thin film Cu 2 SnS 3 and Cu 3 SnS 4 were grown by sulfurization of dc-magnetron sputtered Sn-Cu metallic precursors in a S 2 atmosphere. Different maximum sulfurization temperatures were tested which allowed the study of the Cu 2 SnS 3 phase changes. For a temperature of 350 ºC the films were constituted by tetragonal (I-42m) Cu 2 SnS 3. The films sulfurized at a maximum temperature of 400 ºC presented a cubic (F-43m) Cu 2 SnS 3 phase. Increasing the temperature up to 520 ºC, the Sn content of the layer lowered and orthorhombic (Pmn21) Cu 3 SnS 4 was formed. The phase identification and structural analysis was performed using X-ray Diffraction (XRD) and Electron Back-Scattered Diffraction (EBSD) analysis. Raman scattering analysis was also performed and the comparison with XRD and EBSD data allowed the assignment of peaks at 336 cm -1 and 351 cm -1 for tetragonal Cu 2 SnS 3, 303 cm -1 and 355 cm -1 for cubic Cu 2 SnS 3, and 318 cm -1, 348 cm -1 and 295 cm -1 for the Cu 3 SnS 4 phase. Compositional analysis was done using Energy Dispersive Spectroscopy (EDS) and Induced Coupled Plasma (ICP) analysis. Scanning Electron Microscopy (SEM) was used to study the morphology of the layers. The transmittance and reflectance measurements permitted the estimation the absorbance and the band gap. These ternary compounds present a high absorbance value close to 10 4 cm -1. The estimated band gap energy was 1.35 eV for tetragonal (I-42m) Cu 2 SnS 3, 0.96 eV for cubic (F-43m) Cu 2 SnS 3 and 1.60 eV for orthorhombic (Pmn21) Cu 3 SnS 4. Hot Point Probe was used for the determination of the semiconductor conductivity type. The results show that all samples are p-type semiconductor. Four Point Probe was used to obtain the resistivity of these samples. The resistivity for tetragonal Cu 2 SnS 3, cubic Cu 2 SnS 3 and orthorhombic (Pmn21) Cu 3 SnS 4 are 4.59×10 -2 Ω⋅cm, 1.26×10 -2 Ω⋅cm, 7.40×10 -4 Ω⋅cm, respectively.
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A study of ternary Cu2SnS3 and Cu3SnS4 thin films prepared by sulfurizing stacked metal precursors
Journal of Physics D: Applied Physics, 2010Co-Authors: Paulo Fernandes, P. M. P. Salomé, A. F. Da CunhaAbstract:Thin films of Cu2SnS3 and Cu3SnS4 were grown by sulfurization of dc magnetron sputtered Sn–Cu metallic precursors in a S2 atmosphere. Different maximum sulfurization temperatures were tested which allowed the study of the Cu2SnS3 phase changes. For a temperature of 350 °C the films were composed of tetragonal (I-42m) Cu2SnS3. The films sulfurized at a maximum temperature of 400 °C presented a cubic (F-43m) Cu2SnS3 phase. On increasing the temperature up to 520 °C, the Sn content of the layer decreased and orthorhombic (Pmn21) Cu3SnS4 was formed. The phase identification and structural analysis were performed using x-ray diffraction (XRD) and electron backscattered diffraction (EBSD) analysis. Raman scattering analysis was also performed and a comparison with XRD and EBSD data allowed the assignment of peaks at 336 and 351 cm−1 for tetragonal Cu2SnS3, 303 and 355 cm−1 for cubic Cu2SnS3, and 318, 348 and 295 cm−1 for the Cu3SnS4 phase. Compositional analysis was done using energy dispersive spectroscopy and induced coupled plasma analysis. Scanning electron microscopy was used to study the morphology of the layers. Transmittance and reflectance measurements permitted the estimation of absorbance and band gap. These ternary compounds present a high absorbance value close to 104 cm−1. The estimated band gap energy was 1.35 eV for tetragonal (I-42m) Cu2SnS3, 0.96 eV for cubic (F-43m) Cu2SnS3 and 1.60 eV for orthorhombic (Pmn21) Cu3SnS4. A hot point probe was used for the determination of semiconductor conductivity type. The results show that all the samples are p-type semiconductors. A four-point probe was used to obtain the resistivity of these samples. The resistivities for tetragonal Cu2SnS3, cubic Cu2SnS3 and orthorhombic (Pmn21) Cu3SnS4 are 4.59 × 10−2 Ω cm, 1.26 × 10−2 Ω cm, 7.40 × 10−4 Ω cm, respectively.
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CuxSnSx+1(x = 2, 3) thin films grown by sulfurization of metallic precursors deposited by dc magnetron sputtering
physica status solidi (c), 2010Co-Authors: P. A. Fernandes, P. M. P. Salomé, A. F. Da CunhaAbstract:We report the results of the growth of Cu-Sn-S ternary chalcogenide compounds by sulfurization of dc magnetron sputtered metallic precursors. Tetragonal Cu2SnS3 forms for a maximum sulfurization temperature of 350 ºC. Cubic Cu2SnS3 is obtained at sulfurization temperatures above 400 ºC. These results are supported by XRD analysis and Raman spectroscopy measurements. The latter analysis shows peaks at 336 cm-1, 351 cm-1 for tetragonal Cu2SnS3, and 303 cm-1, 355 cm-1 for cubic Cu2SnS3. Optical analysis shows that this phase change lowers the band gap from 1.35 eV to 0.98 eV. At higher sulfurization temperatures increased loss of Sn is expected in the sulphide form. As a consequence, higher Cu content ternary compounds like Cu3SnS4 grow. In these conditions, XRD and Raman analysis only detected orthorhombic (Pmn21) phase (petrukite). This compound has Raman peaks at 318 cm-1, 348 cm-1 and 295 cm-1. For a sulfurization temperature of 450 ºC the samples present a multi-phase structure mainly composed by cubic Cu2SnS3 and orthorhombic (Pmn21) Cu3SnS4. For higher temperatures, the samples are single phase and constituted by orthorhombic (Pmn21) Cu3SnS4. Transmittance and reflectance measurements were used to estimate a band gap of 1.60 eV. For comparison we also include the results for Cu2ZnSnS4 obtained using similar growth conditions
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CuxSnSx+1 (x = 2, 3) thin films grown by sulfurization of metallic precursors deposited by dc magnetron sputtering
Physica Status Solidi (c), 2010Co-Authors: Paulo Fernandes, P. M. P. Salomé, A. F. Da CunhaAbstract:We report the results of the growth of Cu-Sn-S ternary chalcogenide compounds by sulfurization of dc magnetron sputtered metallic precursors. Tetragonal Cu2SnS3 forms for a maximum sulfurization temperature of 350 °C. Cubic Cu2SnS3 is obtained at sulfurization temperatures above 400 °C. These results are supported by XRD analysis and Raman spectroscopy measurements. The latter analysis shows peaks at 336 cm-1, 351 cm-1 for tetragonal Cu2SnS3, and 303 cm-1, 355 cm-1 for cubic Cu2SnS3. Optical analysis shows that this phase change lowers the band gap from 1.35 eV to 0.98 eV. At higher sulfurization temperatures increased loss of Sn is expected in the sulphide form. As a consequence, higher Cu content ternary compounds like Cu3SnS4 grow. In these conditions, XRD and Raman analysis only detected orthorhombic (Pmn21) phase (petrukite). This compound has Raman peaks at 318 cm-1, 348 cm-1 and 295 cm-1. For a sulfurization temperature of 450 °C the samples present a multi-phase structure mainly composed by cubic Cu2SnS3 and orthorhombic (Pmn21) Cu3SnS4. For higher temperatures, the samples are single phase and constituted by orthorhombic (Pmn21) Cu3SnS4. Transmittance and reflectance measurements were used to estimate a band gap of 1.60 eV. For comparison we also include the results for Cu2ZnSnS4 obtained using similar growth conditions. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
P. M. P. Salomé - One of the best experts on this subject based on the ideXlab platform.
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A study of ternary Cu2SnS3 and Cu3SnS4 thin films prepared by sulfurizing stacked metal precursors
Journal of Physics D: Applied Physics, 2010Co-Authors: P. A. Fernandes, P. M. P. Salomé, A. F. Da CunhaAbstract:Thin film Cu 2 SnS 3 and Cu 3 SnS 4 were grown by sulfurization of dc-magnetron sputtered Sn-Cu metallic precursors in a S 2 atmosphere. Different maximum sulfurization temperatures were tested which allowed the study of the Cu 2 SnS 3 phase changes. For a temperature of 350 ºC the films were constituted by tetragonal (I-42m) Cu 2 SnS 3. The films sulfurized at a maximum temperature of 400 ºC presented a cubic (F-43m) Cu 2 SnS 3 phase. Increasing the temperature up to 520 ºC, the Sn content of the layer lowered and orthorhombic (Pmn21) Cu 3 SnS 4 was formed. The phase identification and structural analysis was performed using X-ray Diffraction (XRD) and Electron Back-Scattered Diffraction (EBSD) analysis. Raman scattering analysis was also performed and the comparison with XRD and EBSD data allowed the assignment of peaks at 336 cm -1 and 351 cm -1 for tetragonal Cu 2 SnS 3, 303 cm -1 and 355 cm -1 for cubic Cu 2 SnS 3, and 318 cm -1, 348 cm -1 and 295 cm -1 for the Cu 3 SnS 4 phase. Compositional analysis was done using Energy Dispersive Spectroscopy (EDS) and Induced Coupled Plasma (ICP) analysis. Scanning Electron Microscopy (SEM) was used to study the morphology of the layers. The transmittance and reflectance measurements permitted the estimation the absorbance and the band gap. These ternary compounds present a high absorbance value close to 10 4 cm -1. The estimated band gap energy was 1.35 eV for tetragonal (I-42m) Cu 2 SnS 3, 0.96 eV for cubic (F-43m) Cu 2 SnS 3 and 1.60 eV for orthorhombic (Pmn21) Cu 3 SnS 4. Hot Point Probe was used for the determination of the semiconductor conductivity type. The results show that all samples are p-type semiconductor. Four Point Probe was used to obtain the resistivity of these samples. The resistivity for tetragonal Cu 2 SnS 3, cubic Cu 2 SnS 3 and orthorhombic (Pmn21) Cu 3 SnS 4 are 4.59×10 -2 Ω⋅cm, 1.26×10 -2 Ω⋅cm, 7.40×10 -4 Ω⋅cm, respectively.
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A study of ternary Cu2SnS3 and Cu3SnS4 thin films prepared by sulfurizing stacked metal precursors
Journal of Physics D: Applied Physics, 2010Co-Authors: Paulo Fernandes, P. M. P. Salomé, A. F. Da CunhaAbstract:Thin films of Cu2SnS3 and Cu3SnS4 were grown by sulfurization of dc magnetron sputtered Sn–Cu metallic precursors in a S2 atmosphere. Different maximum sulfurization temperatures were tested which allowed the study of the Cu2SnS3 phase changes. For a temperature of 350 °C the films were composed of tetragonal (I-42m) Cu2SnS3. The films sulfurized at a maximum temperature of 400 °C presented a cubic (F-43m) Cu2SnS3 phase. On increasing the temperature up to 520 °C, the Sn content of the layer decreased and orthorhombic (Pmn21) Cu3SnS4 was formed. The phase identification and structural analysis were performed using x-ray diffraction (XRD) and electron backscattered diffraction (EBSD) analysis. Raman scattering analysis was also performed and a comparison with XRD and EBSD data allowed the assignment of peaks at 336 and 351 cm−1 for tetragonal Cu2SnS3, 303 and 355 cm−1 for cubic Cu2SnS3, and 318, 348 and 295 cm−1 for the Cu3SnS4 phase. Compositional analysis was done using energy dispersive spectroscopy and induced coupled plasma analysis. Scanning electron microscopy was used to study the morphology of the layers. Transmittance and reflectance measurements permitted the estimation of absorbance and band gap. These ternary compounds present a high absorbance value close to 104 cm−1. The estimated band gap energy was 1.35 eV for tetragonal (I-42m) Cu2SnS3, 0.96 eV for cubic (F-43m) Cu2SnS3 and 1.60 eV for orthorhombic (Pmn21) Cu3SnS4. A hot point probe was used for the determination of semiconductor conductivity type. The results show that all the samples are p-type semiconductors. A four-point probe was used to obtain the resistivity of these samples. The resistivities for tetragonal Cu2SnS3, cubic Cu2SnS3 and orthorhombic (Pmn21) Cu3SnS4 are 4.59 × 10−2 Ω cm, 1.26 × 10−2 Ω cm, 7.40 × 10−4 Ω cm, respectively.
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CuxSnSx+1(x = 2, 3) thin films grown by sulfurization of metallic precursors deposited by dc magnetron sputtering
physica status solidi (c), 2010Co-Authors: P. A. Fernandes, P. M. P. Salomé, A. F. Da CunhaAbstract:We report the results of the growth of Cu-Sn-S ternary chalcogenide compounds by sulfurization of dc magnetron sputtered metallic precursors. Tetragonal Cu2SnS3 forms for a maximum sulfurization temperature of 350 ºC. Cubic Cu2SnS3 is obtained at sulfurization temperatures above 400 ºC. These results are supported by XRD analysis and Raman spectroscopy measurements. The latter analysis shows peaks at 336 cm-1, 351 cm-1 for tetragonal Cu2SnS3, and 303 cm-1, 355 cm-1 for cubic Cu2SnS3. Optical analysis shows that this phase change lowers the band gap from 1.35 eV to 0.98 eV. At higher sulfurization temperatures increased loss of Sn is expected in the sulphide form. As a consequence, higher Cu content ternary compounds like Cu3SnS4 grow. In these conditions, XRD and Raman analysis only detected orthorhombic (Pmn21) phase (petrukite). This compound has Raman peaks at 318 cm-1, 348 cm-1 and 295 cm-1. For a sulfurization temperature of 450 ºC the samples present a multi-phase structure mainly composed by cubic Cu2SnS3 and orthorhombic (Pmn21) Cu3SnS4. For higher temperatures, the samples are single phase and constituted by orthorhombic (Pmn21) Cu3SnS4. Transmittance and reflectance measurements were used to estimate a band gap of 1.60 eV. For comparison we also include the results for Cu2ZnSnS4 obtained using similar growth conditions
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CuxSnSx+1 (x = 2, 3) thin films grown by sulfurization of metallic precursors deposited by dc magnetron sputtering
Physica Status Solidi (c), 2010Co-Authors: Paulo Fernandes, P. M. P. Salomé, A. F. Da CunhaAbstract:We report the results of the growth of Cu-Sn-S ternary chalcogenide compounds by sulfurization of dc magnetron sputtered metallic precursors. Tetragonal Cu2SnS3 forms for a maximum sulfurization temperature of 350 °C. Cubic Cu2SnS3 is obtained at sulfurization temperatures above 400 °C. These results are supported by XRD analysis and Raman spectroscopy measurements. The latter analysis shows peaks at 336 cm-1, 351 cm-1 for tetragonal Cu2SnS3, and 303 cm-1, 355 cm-1 for cubic Cu2SnS3. Optical analysis shows that this phase change lowers the band gap from 1.35 eV to 0.98 eV. At higher sulfurization temperatures increased loss of Sn is expected in the sulphide form. As a consequence, higher Cu content ternary compounds like Cu3SnS4 grow. In these conditions, XRD and Raman analysis only detected orthorhombic (Pmn21) phase (petrukite). This compound has Raman peaks at 318 cm-1, 348 cm-1 and 295 cm-1. For a sulfurization temperature of 450 °C the samples present a multi-phase structure mainly composed by cubic Cu2SnS3 and orthorhombic (Pmn21) Cu3SnS4. For higher temperatures, the samples are single phase and constituted by orthorhombic (Pmn21) Cu3SnS4. Transmittance and reflectance measurements were used to estimate a band gap of 1.60 eV. For comparison we also include the results for Cu2ZnSnS4 obtained using similar growth conditions. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Paulo Fernandes - One of the best experts on this subject based on the ideXlab platform.
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A study of ternary Cu2SnS3 and Cu3SnS4 thin films prepared by sulfurizing stacked metal precursors
Journal of Physics D: Applied Physics, 2010Co-Authors: Paulo Fernandes, P. M. P. Salomé, A. F. Da CunhaAbstract:Thin films of Cu2SnS3 and Cu3SnS4 were grown by sulfurization of dc magnetron sputtered Sn–Cu metallic precursors in a S2 atmosphere. Different maximum sulfurization temperatures were tested which allowed the study of the Cu2SnS3 phase changes. For a temperature of 350 °C the films were composed of tetragonal (I-42m) Cu2SnS3. The films sulfurized at a maximum temperature of 400 °C presented a cubic (F-43m) Cu2SnS3 phase. On increasing the temperature up to 520 °C, the Sn content of the layer decreased and orthorhombic (Pmn21) Cu3SnS4 was formed. The phase identification and structural analysis were performed using x-ray diffraction (XRD) and electron backscattered diffraction (EBSD) analysis. Raman scattering analysis was also performed and a comparison with XRD and EBSD data allowed the assignment of peaks at 336 and 351 cm−1 for tetragonal Cu2SnS3, 303 and 355 cm−1 for cubic Cu2SnS3, and 318, 348 and 295 cm−1 for the Cu3SnS4 phase. Compositional analysis was done using energy dispersive spectroscopy and induced coupled plasma analysis. Scanning electron microscopy was used to study the morphology of the layers. Transmittance and reflectance measurements permitted the estimation of absorbance and band gap. These ternary compounds present a high absorbance value close to 104 cm−1. The estimated band gap energy was 1.35 eV for tetragonal (I-42m) Cu2SnS3, 0.96 eV for cubic (F-43m) Cu2SnS3 and 1.60 eV for orthorhombic (Pmn21) Cu3SnS4. A hot point probe was used for the determination of semiconductor conductivity type. The results show that all the samples are p-type semiconductors. A four-point probe was used to obtain the resistivity of these samples. The resistivities for tetragonal Cu2SnS3, cubic Cu2SnS3 and orthorhombic (Pmn21) Cu3SnS4 are 4.59 × 10−2 Ω cm, 1.26 × 10−2 Ω cm, 7.40 × 10−4 Ω cm, respectively.
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CuxSnSx+1 (x = 2, 3) thin films grown by sulfurization of metallic precursors deposited by dc magnetron sputtering
Physica Status Solidi (c), 2010Co-Authors: Paulo Fernandes, P. M. P. Salomé, A. F. Da CunhaAbstract:We report the results of the growth of Cu-Sn-S ternary chalcogenide compounds by sulfurization of dc magnetron sputtered metallic precursors. Tetragonal Cu2SnS3 forms for a maximum sulfurization temperature of 350 °C. Cubic Cu2SnS3 is obtained at sulfurization temperatures above 400 °C. These results are supported by XRD analysis and Raman spectroscopy measurements. The latter analysis shows peaks at 336 cm-1, 351 cm-1 for tetragonal Cu2SnS3, and 303 cm-1, 355 cm-1 for cubic Cu2SnS3. Optical analysis shows that this phase change lowers the band gap from 1.35 eV to 0.98 eV. At higher sulfurization temperatures increased loss of Sn is expected in the sulphide form. As a consequence, higher Cu content ternary compounds like Cu3SnS4 grow. In these conditions, XRD and Raman analysis only detected orthorhombic (Pmn21) phase (petrukite). This compound has Raman peaks at 318 cm-1, 348 cm-1 and 295 cm-1. For a sulfurization temperature of 450 °C the samples present a multi-phase structure mainly composed by cubic Cu2SnS3 and orthorhombic (Pmn21) Cu3SnS4. For higher temperatures, the samples are single phase and constituted by orthorhombic (Pmn21) Cu3SnS4. Transmittance and reflectance measurements were used to estimate a band gap of 1.60 eV. For comparison we also include the results for Cu2ZnSnS4 obtained using similar growth conditions. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
P. A. Fernandes - One of the best experts on this subject based on the ideXlab platform.
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A study of ternary Cu2SnS3 and Cu3SnS4 thin films prepared by sulfurizing stacked metal precursors
Journal of Physics D: Applied Physics, 2010Co-Authors: P. A. Fernandes, P. M. P. Salomé, A. F. Da CunhaAbstract:Thin film Cu 2 SnS 3 and Cu 3 SnS 4 were grown by sulfurization of dc-magnetron sputtered Sn-Cu metallic precursors in a S 2 atmosphere. Different maximum sulfurization temperatures were tested which allowed the study of the Cu 2 SnS 3 phase changes. For a temperature of 350 ºC the films were constituted by tetragonal (I-42m) Cu 2 SnS 3. The films sulfurized at a maximum temperature of 400 ºC presented a cubic (F-43m) Cu 2 SnS 3 phase. Increasing the temperature up to 520 ºC, the Sn content of the layer lowered and orthorhombic (Pmn21) Cu 3 SnS 4 was formed. The phase identification and structural analysis was performed using X-ray Diffraction (XRD) and Electron Back-Scattered Diffraction (EBSD) analysis. Raman scattering analysis was also performed and the comparison with XRD and EBSD data allowed the assignment of peaks at 336 cm -1 and 351 cm -1 for tetragonal Cu 2 SnS 3, 303 cm -1 and 355 cm -1 for cubic Cu 2 SnS 3, and 318 cm -1, 348 cm -1 and 295 cm -1 for the Cu 3 SnS 4 phase. Compositional analysis was done using Energy Dispersive Spectroscopy (EDS) and Induced Coupled Plasma (ICP) analysis. Scanning Electron Microscopy (SEM) was used to study the morphology of the layers. The transmittance and reflectance measurements permitted the estimation the absorbance and the band gap. These ternary compounds present a high absorbance value close to 10 4 cm -1. The estimated band gap energy was 1.35 eV for tetragonal (I-42m) Cu 2 SnS 3, 0.96 eV for cubic (F-43m) Cu 2 SnS 3 and 1.60 eV for orthorhombic (Pmn21) Cu 3 SnS 4. Hot Point Probe was used for the determination of the semiconductor conductivity type. The results show that all samples are p-type semiconductor. Four Point Probe was used to obtain the resistivity of these samples. The resistivity for tetragonal Cu 2 SnS 3, cubic Cu 2 SnS 3 and orthorhombic (Pmn21) Cu 3 SnS 4 are 4.59×10 -2 Ω⋅cm, 1.26×10 -2 Ω⋅cm, 7.40×10 -4 Ω⋅cm, respectively.
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CuxSnSx+1(x = 2, 3) thin films grown by sulfurization of metallic precursors deposited by dc magnetron sputtering
physica status solidi (c), 2010Co-Authors: P. A. Fernandes, P. M. P. Salomé, A. F. Da CunhaAbstract:We report the results of the growth of Cu-Sn-S ternary chalcogenide compounds by sulfurization of dc magnetron sputtered metallic precursors. Tetragonal Cu2SnS3 forms for a maximum sulfurization temperature of 350 ºC. Cubic Cu2SnS3 is obtained at sulfurization temperatures above 400 ºC. These results are supported by XRD analysis and Raman spectroscopy measurements. The latter analysis shows peaks at 336 cm-1, 351 cm-1 for tetragonal Cu2SnS3, and 303 cm-1, 355 cm-1 for cubic Cu2SnS3. Optical analysis shows that this phase change lowers the band gap from 1.35 eV to 0.98 eV. At higher sulfurization temperatures increased loss of Sn is expected in the sulphide form. As a consequence, higher Cu content ternary compounds like Cu3SnS4 grow. In these conditions, XRD and Raman analysis only detected orthorhombic (Pmn21) phase (petrukite). This compound has Raman peaks at 318 cm-1, 348 cm-1 and 295 cm-1. For a sulfurization temperature of 450 ºC the samples present a multi-phase structure mainly composed by cubic Cu2SnS3 and orthorhombic (Pmn21) Cu3SnS4. For higher temperatures, the samples are single phase and constituted by orthorhombic (Pmn21) Cu3SnS4. Transmittance and reflectance measurements were used to estimate a band gap of 1.60 eV. For comparison we also include the results for Cu2ZnSnS4 obtained using similar growth conditions
Gang Xue - One of the best experts on this subject based on the ideXlab platform.
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Structures and Non-linear Optical Properties of Multi-Sulfur π-Conjugated Compounds 4,5-Vinylenedithio-1,3-dithiole-2-thione (C5H2S5) and 4,5-Vinylenedithio-1,3-dithiole-2-one (C5H2OS4)
Journal of Chemical Crystallography, 2007Co-Authors: Gang Xue, Qi Fang, Xia Chen, Hong LeiAbstract:Both the title multi-sulfur molecules C5H2S5 (1) and C5H2OS4 (2) have a chair conformation, while molecule 1 has a higher degree of π-conjugation. Both the crystals are characterized by short S···S intermolecular contacts and by face-to-face column-like packing style, but crystal 1 has been more stabilized which may be the result of its stronger π–π intermolecular interactions. Compound 1 crystallizes in non-centrosymmetric polar space group Pmn21 with a = 10.6826(17), b = 9.3633(11), c = 4.0764(6) A, V = 407.74(10) A3, and Z = 2. The molecular dipole moment of 1 is ±62.5(1)° away from the macro-polarization direction along the c-axis. Consequently, the crystalline powder of crystal 1 exhibit a second harmonic generating (SHG) intensity 0.5 time strong as that of urea standard powder crystals when irradiated by a 1,080 nm of Nd:YAP laser beam. Compound 2 shows no SHG effect because it crystallizes in centrosymmtric space group Pbca with a = 11.4208(8), b = 7.8843(9), c = 33.587(3) A, V = 3024.3(5) A3, and Z = 16. Structures and Non-linear Optical Properties of Multi-Sulfur π-Conjugated Compounds 4,5-Vinylenedithio-1,3-dithiole-2-thione (C5H2S5) and 4,5-Vinylenedithio-1,3-dithiole-2-one (C5H2OS4) Gang Xue, Qi Fang,* Wen-Tao Yu, Xia Chen, and Hong Lei Compound C5H2S5 crystallizes in the polar space group Pmn21 and its crystalline powder exhibits a second harmonic generating (SHG) intensity 0.5 times that of urea standard (1080 nm → 540 nm), while the similar compound C5H2OS4 has no SHG effect because of its centrosymmetric space group Pbca.
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Syntheses, structures and second-order nonlinear optical properties of octupolar compounds: 2,4,6-tri-substituted s-triazine
Chemical Physics Letters, 2003Co-Authors: Yuezhi Cui, Qi Fang, Hong Lei, Gang XueAbstract:Abstract Three compounds with three p-substituted styryls attaching to the central s-triazine have been synthesized and two crystals determined to be in non-centrosymmetric Cmc21 and Pmn21 space groups, respectively. All of them in solid state are second harmonic generation (SHG) active and two of them show powder SHG intensities one order of magnitude that of urea.