The Experts below are selected from a list of 28470 Experts worldwide ranked by ideXlab platform
Hendrik Hölscher - One of the best experts on this subject based on the ideXlab platform.
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influence of the Ga Content on the optical and electrical properties of cuin _ bm 1 hbox bm x Ga _ bm x se _ bm 2 thin film solar cells
Photovoltaic Specialists Conference, 2013Co-Authors: Zhenhao Zhang, Wolfram Witte, Michael Powalla, Uli Lemmer, Oliver Kiowski, Hendrik HölscherAbstract:Thin-film solar cells that are based on Cu(In,Ga)Se 2 (CIGS) absorbers with Ga/(Ga+In)-ratios from 0 to 1 are fabricated, and their optical and electrical properties are investiGated by macroscopic (current density-voltage, external quantum efficiency) and microscopic (Kelvin probe force microscopy on untreated cross sections of solar cells) measurements. Combining all results, the diffusion voltages of individual solar cells are deduced and compared with the directly measured open-circuit voltages. An increasing splitoff between the diffusion voltage and the opencircuit voltage is observed forGa addition,which indicates a higher recombination rate of photogenerated charge carriers in solar cells with higher Ga Content.
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Influence of the Ga Content on the Optical and Electrical Properties of CuIn $_{{\bm 1}\hbox{--}{\bm x}}$ Ga $_{\bm x}$ Se $_{\bm 2}$ Thin-Film Solar Cells
IEEE Journal of Photovoltaics, 2013Co-Authors: Zhenhao Zhang, Wolfram Witte, Michael Powalla, Uli Lemmer, Oliver Kiowski, Hendrik HölscherAbstract:Thin-film solar cells that are based on Cu(In,Ga)Se 2 (CIGS) absorbers with Ga/(Ga+In)-ratios from 0 to 1 are fabricated, and their optical and electrical properties are investiGated by macroscopic (current density-voltage, external quantum efficiency) and microscopic (Kelvin probe force microscopy on untreated cross sections of solar cells) measurements. Combining all results, the diffusion voltages of individual solar cells are deduced and compared with the directly measured open-circuit voltages. An increasing splitoff between the diffusion voltage and the opencircuit voltage is observed forGa addition,which indicates a higher recombination rate of photogenerated charge carriers in solar cells with higher Ga Content.
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Analysis of untreated cross sections of Cu(In,Ga)Se2 thin-film solar cells with varying Ga Content using Kelvin probe force microscopy
Applied Physics Letters, 2011Co-Authors: Zhenhao Zhang, Wolfram Witte, Michael Powalla, Xiaochen Tang, Uli Lemmer, Oliver Kiowski, Hendrik HölscherAbstract:The potential distribution of the Cu(In,Ga)Se2/CdS/ZnO layer structure on untreated cross sections of Cu(In,Ga)Se2 thin-film solar cells are analyzed by Kelvin probe force microscopy under ambient conditions. The potential differences between the Cu(In,Ga)Se2 absorber and the ZnO window layer are systematically investiGated, providing direct evidence for a Fermi energy shifting in Cu(In,Ga)Se2 absorbers with different Ga Content.
Haruyuki Inui - One of the best experts on this subject based on the ideXlab platform.
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Crystal structure and thermoelectric properties of type-I clathrate compounds in the Ba-Ga-Ge system
Journal of Applied Physics, 2006Co-Authors: Norihiko L. Okamoto, Kyosuke Kishida, Katsushi Tanaka, Haruyuki InuiAbstract:The crystal structure and thermoelectric properties of type-I clathrate compounds in the Ba–Ga–Ge system have been investiGated as a function of Ga Content. The solid solubility of Ga in the type-I clathrate compounds is determined to be X=16 when expressed with the formula of Ba8GaXGe46−X. As the Ga Content increases, the crystal structure changes from a superlattice structure to the normal type-I clathrate structure with the transition occurring at X=3.5–5. The density of Ge vacancies in the type-I clathrate phase decreases as the Ga Content increases. The absolute values of electrical resistivity and Seebeck coefficient increase, while that of lattice thermal conductivity decreases with the increase in the Ga Content. The changes in electrical resistivity and Seebeck coefficient are explained in terms of the number of excess electrons, while the change in lattice thermal conductivity is explained in terms of the extent of the rattling motion of Ba atoms encapsulated in the cage structure.
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High thermoelectric performance of type-III clathrate compounds of the Ba-Ge-Ga system
Acta Materialia, 2006Co-Authors: Jung-hwan Kim, Norihiko L. Okamoto, Kyosuke Kishida, Katsushi Tanaka, Haruyuki InuiAbstract:Abstract The thermoelectric properties of type-III clathrate compounds, Ba 24 Ga X Ge 100− X , have been investiGated as a function of Ga Content and temperature. The substitution of Ga atoms for Ge atoms leads to a decrease of carrier (electron) concentration. Electrical conduction is of n-type for all clathrate compounds investiGated and the values of electrical resistivity and Seebeck coefficient increase with increasing Ga Content and temperature. Both electronic and lattice thermal conductivities decrease with an increase in Ga Content because of the decreased carrier concentration and the increased extent of the rattling motion of Ba atoms encapsulated in open dodecahedrons, respectively. A very high thermoelectric figure of merit (ZT) value of 1.25 is obtained at 670 °C when X = 15.
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Effect of Ga-doping on the Thermoelectric Properties of Ba-Ge Type-III Clathrate Compounds
MRS Proceedings, 2005Co-Authors: Jung-hwan Kim, Norihiko L. Okamoto, Katsushi Tanaka, Haruyuki InuiAbstract:ABSTRACTEffect of Ga addition on the thermoelectric properties of Ba-Ge type-III clathrate has been investiGated as a function of Ga Content and temperature. The substitution of Ga atom for Ge atom leads to the decrease of carrier (electron) concentration. Electrical conduction is of n-type for all clathrate compounds investiGated and the values of electrical resistivity and Seebeck coefficient increase with the increase in the Ga Content and in temperature. Both electronic and lattice thermal conductivity decrease with the increase in the Ga Content because of the decreased carrier concentration and the increased extent of the rattling motion of Ba atoms encapsulated in open-dodecahedron, respectively. A very high ZT value of 1.25 is obtained at 670 °C for Ba24Ga15Ge85.
Kwang-lung Lin - One of the best experts on this subject based on the ideXlab platform.
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Effect of Ga on the Oxidation Properties of Sn-8.5Zn-0.5Ag-0.1Al-xGa Solders
Oxidation of Metals, 2012Co-Authors: Nai-shuo Liu, Kwang-lung LinAbstract:The oxidation properties of Sn–8.5Zn–0.5Ag–0.1Al–xGa lead-free solders in the liquid state (250 °C) under O2 atmosphere were investiGated using a thermal gravimetric analyzer. The Ga Content of the investiGated solders was 0.05–2 wt%. The results indicate that Ga enhances the oxidation resistance of Sn–Zn–Ag–Al solder. Cross-sections of the solder surfaces were examined using focus ion beam milling. The thickness of the oxidation layer, which was about 30–100 nm, increased with increasing Ga Content. The oxidation layer was found to be nonuniform at low Ga Content. The oxide layers on the surface of solders were investiGated using Auger electron spectroscopy and thin-film XRD. The results showed that the oxide layer formed was ZnO. Al and Ga tended to segreGate on the surface of the solder.
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The effect of Ga Content on the wetting reaction and interfacial morphology formed between Sn–8.55Zn–0.5Ag–0.1Al–xGa solders and Cu
Scripta Materialia, 2006Co-Authors: Nai-shuo Liu, Kwang-lung LinAbstract:Abstract The wetting properties of Sn–8.5Zn–0.5Ag–0.1Al– x Ga lead-free solders were investiGated. The wetting time and wetting angle decreased while the wetting force increased with the increase in Ga Content. The intermetallic compounds were Al 4.2 Cu 3.2 Zn 0.7 , Cu 5 Zn 8 , Cu 5 Zn 8 and AgZn 3 in the solder. The activation energy and the surface tension of the solder were estimated.
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the effect of Ga Content on the wetting reaction and interfacial morphology formed between sn 8 55zn 0 5ag 0 1al xGa solders and cu
Scripta Materialia, 2006Co-Authors: Nai-shuo Liu, Kwang-lung LinAbstract:Abstract The wetting properties of Sn–8.5Zn–0.5Ag–0.1Al– x Ga lead-free solders were investiGated. The wetting time and wetting angle decreased while the wetting force increased with the increase in Ga Content. The intermetallic compounds were Al 4.2 Cu 3.2 Zn 0.7 , Cu 5 Zn 8 , Cu 5 Zn 8 and AgZn 3 in the solder. The activation energy and the surface tension of the solder were estimated.
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microstructure and mechanical properties of low Ga Content sn 8 55zn 0 5ag 0 1al xGa solders
Scripta Materialia, 2005Co-Authors: Nai-shuo Liu, Kwang-lung LinAbstract:Abstract The Sn–8.5Zn–0.5Ag–0.1Al– x Ga solders were investiGated. The results showed that the microstructure of the solders were eutectic. The addition of Ga dramatically decreased the melting point of solders. Notably, the increase in Ga Content of the solder improved the solderability, the tensile strength and reduced the ductility.
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Microstructure and mechanical properties of low Ga Content Sn–8.55Zn–0.5Ag–0.1Al–xGa solders
Scripta Materialia, 2005Co-Authors: Nai-shuo Liu, Kwang-lung LinAbstract:Abstract The Sn–8.5Zn–0.5Ag–0.1Al– x Ga solders were investiGated. The results showed that the microstructure of the solders were eutectic. The addition of Ga dramatically decreased the melting point of solders. Notably, the increase in Ga Content of the solder improved the solderability, the tensile strength and reduced the ductility.
Zhenhao Zhang - One of the best experts on this subject based on the ideXlab platform.
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influence of the Ga Content on the optical and electrical properties of cuin _ bm 1 hbox bm x Ga _ bm x se _ bm 2 thin film solar cells
Photovoltaic Specialists Conference, 2013Co-Authors: Zhenhao Zhang, Wolfram Witte, Michael Powalla, Uli Lemmer, Oliver Kiowski, Hendrik HölscherAbstract:Thin-film solar cells that are based on Cu(In,Ga)Se 2 (CIGS) absorbers with Ga/(Ga+In)-ratios from 0 to 1 are fabricated, and their optical and electrical properties are investiGated by macroscopic (current density-voltage, external quantum efficiency) and microscopic (Kelvin probe force microscopy on untreated cross sections of solar cells) measurements. Combining all results, the diffusion voltages of individual solar cells are deduced and compared with the directly measured open-circuit voltages. An increasing splitoff between the diffusion voltage and the opencircuit voltage is observed forGa addition,which indicates a higher recombination rate of photogenerated charge carriers in solar cells with higher Ga Content.
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Influence of the Ga Content on the Optical and Electrical Properties of CuIn $_{{\bm 1}\hbox{--}{\bm x}}$ Ga $_{\bm x}$ Se $_{\bm 2}$ Thin-Film Solar Cells
IEEE Journal of Photovoltaics, 2013Co-Authors: Zhenhao Zhang, Wolfram Witte, Michael Powalla, Uli Lemmer, Oliver Kiowski, Hendrik HölscherAbstract:Thin-film solar cells that are based on Cu(In,Ga)Se 2 (CIGS) absorbers with Ga/(Ga+In)-ratios from 0 to 1 are fabricated, and their optical and electrical properties are investiGated by macroscopic (current density-voltage, external quantum efficiency) and microscopic (Kelvin probe force microscopy on untreated cross sections of solar cells) measurements. Combining all results, the diffusion voltages of individual solar cells are deduced and compared with the directly measured open-circuit voltages. An increasing splitoff between the diffusion voltage and the opencircuit voltage is observed forGa addition,which indicates a higher recombination rate of photogenerated charge carriers in solar cells with higher Ga Content.
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Analysis of untreated cross sections of Cu(In,Ga)Se2 thin-film solar cells with varying Ga Content using Kelvin probe force microscopy
Applied Physics Letters, 2011Co-Authors: Zhenhao Zhang, Wolfram Witte, Michael Powalla, Xiaochen Tang, Uli Lemmer, Oliver Kiowski, Hendrik HölscherAbstract:The potential distribution of the Cu(In,Ga)Se2/CdS/ZnO layer structure on untreated cross sections of Cu(In,Ga)Se2 thin-film solar cells are analyzed by Kelvin probe force microscopy under ambient conditions. The potential differences between the Cu(In,Ga)Se2 absorber and the ZnO window layer are systematically investiGated, providing direct evidence for a Fermi energy shifting in Cu(In,Ga)Se2 absorbers with different Ga Content.
Nai-shuo Liu - One of the best experts on this subject based on the ideXlab platform.
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Effect of Ga on the Oxidation Properties of Sn–8.5Zn–0.5Ag–0.1Al–xGa Solders
Oxidation of Metals, 2012Co-Authors: Nai-shuo LiuAbstract:The oxidation properties of Sn–8.5Zn–0.5Ag–0.1Al– x Ga lead-free solders in the liquid state (250 °C) under O_2 atmosphere were investiGated using a thermal gravimetric analyzer. The Ga Content of the investiGated solders was 0.05–2 wt%. The results indicate that Ga enhances the oxidation resistance of Sn–Zn–Ag–Al solder. Cross-sections of the solder surfaces were examined using focus ion beam milling. The thickness of the oxidation layer, which was about 30–100 nm, increased with increasing Ga Content. The oxidation layer was found to be nonuniform at low Ga Content. The oxide layers on the surface of solders were investiGated using Auger electron spectroscopy and thin-film XRD. The results showed that the oxide layer formed was ZnO. Al and Ga tended to segreGate on the surface of the solder.
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Effect of Ga on the Oxidation Properties of Sn-8.5Zn-0.5Ag-0.1Al-xGa Solders
Oxidation of Metals, 2012Co-Authors: Nai-shuo Liu, Kwang-lung LinAbstract:The oxidation properties of Sn–8.5Zn–0.5Ag–0.1Al–xGa lead-free solders in the liquid state (250 °C) under O2 atmosphere were investiGated using a thermal gravimetric analyzer. The Ga Content of the investiGated solders was 0.05–2 wt%. The results indicate that Ga enhances the oxidation resistance of Sn–Zn–Ag–Al solder. Cross-sections of the solder surfaces were examined using focus ion beam milling. The thickness of the oxidation layer, which was about 30–100 nm, increased with increasing Ga Content. The oxidation layer was found to be nonuniform at low Ga Content. The oxide layers on the surface of solders were investiGated using Auger electron spectroscopy and thin-film XRD. The results showed that the oxide layer formed was ZnO. Al and Ga tended to segreGate on the surface of the solder.
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The effect of Ga Content on the wetting reaction and interfacial morphology formed between Sn–8.55Zn–0.5Ag–0.1Al–xGa solders and Cu
Scripta Materialia, 2006Co-Authors: Nai-shuo Liu, Kwang-lung LinAbstract:Abstract The wetting properties of Sn–8.5Zn–0.5Ag–0.1Al– x Ga lead-free solders were investiGated. The wetting time and wetting angle decreased while the wetting force increased with the increase in Ga Content. The intermetallic compounds were Al 4.2 Cu 3.2 Zn 0.7 , Cu 5 Zn 8 , Cu 5 Zn 8 and AgZn 3 in the solder. The activation energy and the surface tension of the solder were estimated.
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the effect of Ga Content on the wetting reaction and interfacial morphology formed between sn 8 55zn 0 5ag 0 1al xGa solders and cu
Scripta Materialia, 2006Co-Authors: Nai-shuo Liu, Kwang-lung LinAbstract:Abstract The wetting properties of Sn–8.5Zn–0.5Ag–0.1Al– x Ga lead-free solders were investiGated. The wetting time and wetting angle decreased while the wetting force increased with the increase in Ga Content. The intermetallic compounds were Al 4.2 Cu 3.2 Zn 0.7 , Cu 5 Zn 8 , Cu 5 Zn 8 and AgZn 3 in the solder. The activation energy and the surface tension of the solder were estimated.
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microstructure and mechanical properties of low Ga Content sn 8 55zn 0 5ag 0 1al xGa solders
Scripta Materialia, 2005Co-Authors: Nai-shuo Liu, Kwang-lung LinAbstract:Abstract The Sn–8.5Zn–0.5Ag–0.1Al– x Ga solders were investiGated. The results showed that the microstructure of the solders were eutectic. The addition of Ga dramatically decreased the melting point of solders. Notably, the increase in Ga Content of the solder improved the solderability, the tensile strength and reduced the ductility.
