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Cu2SnS3 (CTS) is a promising compound for use as an absorber layer in thin-film solar cells because it is made up of low-cost and abundant elements. However, the band gap energy of 0.94 eV for monoclinic Cu2SnS3 is less than the optimal value for absorber layers in single-junction solar cells. On the other hand, the band gap energy of Cu2GeS3 (CGS) is approximately 1.5-1.6 eV. Therefore, in this study, we carried out the synthesis of Cu2Sn1− xGe xS3, which is a solid solution of Cu2SnS3 and Cu2GeS3. The structure of the prepared samples was investigated using X-ray diffraction and Raman analyses. Diffuse reflectance spectra were obtained using a UV-Vis-NIR spectrometer and used to estimate the band gap energy. In X-ray diffraction patterns from the synthesized compounds, the diffraction peaks were found to shift to higher 2 θ values with increasing x, indicating a decrease in the lattice constants. In addition, the estimated band gap energy increased from 0.86 to 1.53 eV with increasing x. Cu2Sn1 − xGe xS3 is, therefore, a potential candidate for use as the absorber layer in thin film solar cells because its band gap energy can be adjusted simply by varying its composition. [ABSTRACT FROM AUTHOR]

We have measured photoluminescence (PL) spectra at 10 K for Cu2ZnSnS4 (CZTS) single crystals grown by the iodine transport method and explored the anneal changes of PL spectra under a Zn and S-saturation. All the crystals showed S- and Zn-poor composition, and nearly stoichiometric composition of Cu/(Zn + Sn). The observed PL spectra are divided into two groups; one is PL band with a peak at ∼1.3 eV (1.3-eV band), and another is PL band with a peak at ∼1.35 eV (1.35-eV band). It was found from SEM observations that the 1.35-eV band was observed in crystals with a mirror-like facet and, on the other hand, the 1.3-eV band was seen in the crystals with some small dark areas where the composition is Cu-poor. The Zn-saturated annealing at 600 °C caused the PL peak shift of ∼0.1 eV, from 1.295 to 1.185 eV. The S-saturated annealing at 550 °C caused a disappearance of PL emission. The implications of these annealing behaviour are discussed. [ABSTRACT FROM AUTHOR]

Cu2Sn1 −xGe xS3 (CTGS) thin films were prepared by co-evaporation of Cu, Sn, and S to form Cu2SnS3 (CTS) precursors, which were then annealed at 570 °C in an atmosphere composed of N2, GeS2, and S vapor. The films were then used to fabricate photovoltaic cells with the structure glass/Mo/CTGS/CdS/ZnO:Al/Al. A cell with a film composition of Cu2(Sn0.86Ge0.14)S3 fabricated from slightly Cu-rich CTS (Cu/Sn = 2.07) exhibited a conversion efficiency of 3.4% and an open-circuit voltage of 0.29 V. The band gap based on the external quantum efficiency was estimated to be approximately 1.0 eV. The open-circuit voltage was found to be larger than that for a CTS thin film solar cell and increased with band gap energy. [ABSTRACT FROM AUTHOR]

The organic-inorganic hybrid perovskite CH3NH3PbI3 thin-films were obtained by reaction between spin-coated PbI2 precursor thin-films on a porous-TiO2 layer and CH3NH3I vapor. The dependence of the photovoltaic properties of solar cells fabricated with these films on the CH3NH3I powder source temperature and reaction time was investigated. The obtained thin-films were characterized using X-ray diffraction and scanning electron microscopy. The best power conversion efficiencies (PCEs) for each heating condition were 160 °C for 30 min, 150 °C for 45 min, and 140 °C for 60 min. The presence of PbI2 and CH3NH3PbI3 layers, and a flatter and more compact morphology, led to relatively high PCE. The perovskite thin-films were annealed in a N2 atmosphere and the effect of annealing temperature on the photovoltaic performance was also investigated. The PCE for a solar cell fabricated using CH3NH3PbI3 thin-films annealed in the range from 130 to 150 °C for 1 h was over 4%. [ABSTRACT FROM AUTHOR]

The binary compound SnS consists of elements that are non-toxic, inexpensive, and abundant in the Earth's crust. It is a p-type semiconductor with a band gap energy of 1.3 eV and an absorption coefficient of 104 cm−1, and is therefore a potential candidate for use as a solar cell absorber material. In this study, SLG/Mo/SnS/CdS/ZnO:Al/Al and SLG/Mo/SnS/ZnO/ZnO:Al/Al SnS thin-film solar cells with different buffer layers were fabricated using a co-evaporation method. The dependence of the photovoltaic properties of the SnS thin-film solar cells with CdS or ZnO as the buffer layer was investigated. We demonstrate that the device with a ZnO buffer layer exhibited higher conversion efficiency and short-circuit current density compared to the device with a CdS buffer layer. [ABSTRACT FROM AUTHOR]

Cu2SnS3 (CTS) is a promising compound for use as an absorber layer in thin-film solar cells because it is made up of low-cost and abundant elements. However, the band gap energy of 0.94 eV for monoclinic Cu2SnS3 is less than the optimal value for absorber layers in single-junction solar cells. On the other hand, the band gap energy of Cu2GeS3 (CGS) is approximately 1.5-1.6 eV. Therefore, in this study, we carried out the synthesis of Cu2Sn1− xGe xS3, which is a solid solution of Cu2SnS3 and Cu2GeS3. The structure of the prepared samples was investigated using X-ray diffraction and Raman analyses. Diffuse reflectance spectra were obtained using a UV-Vis-NIR spectrometer and used to estimate the band gap energy. In X-ray diffraction patterns from the synthesized compounds, the diffraction peaks were found to shift to higher 2 θ values with increasing x, indicating a decrease in the lattice constants. In addition, the estimated band gap energy increased from 0.86 to 1.53 eV with increasing x. Cu2Sn1 − xGe xS3 is, therefore, a potential candidate for use as the absorber layer in thin film solar cells because its band gap energy can be adjusted simply by varying its composition. [ABSTRACT FROM AUTHOR]

We investigated the effect of H2S annealing for glass/Ag/Sn and glass/Ag/SnS precursor thin films deposited by vacuum evaporation. The glass/Ag/Sn and glass/Ag/SnS stacked precursors were deposited on soda-lime glass substrates at 300 °C. After the evaporation, the stacked precursors were annealed from 300 to 500 °C for 60 min in H2S atmosphere. A Ag8SnS6 thin films can be prepared with Ag2SnS3 and SnS2 crystals. The grain size of the crystals in the thin films using a glass/Ag/SnS stacked precursor was larger than that using a glass/Ag/Sn stacked precursor. The absorption coefficients and band-gap energy of Ag-Sn-S thin films with Ag8SnS6, Ag2SnS3, and SnS2 crystals were above 104 cm−1 and approximately 1.3 eV, respectively. [ABSTRACT FROM AUTHOR]

The ternary compound Cu2SnS3 (CTS) is composed of elements that are low in cost, non-toxic, and abundant in the Earth's crust. In addition, CTS is a p-type semiconductor with a high reported absorption coefficient of more than 104 cm−1 and a band gap energy of 0.92-1.77 eV. It is, therefore, considered to be a suitable candidate for the absorber layer in thin film solar cells. In the present study, CTS thin films were produced by first depositing precursor films by co-evaporation of Cu, Sn, and S, and then annealing them. Solar cells were then fabricated using the CTS films as absorber layers, and the dependence of their photovoltaic properties on the annealing temperature was investigated. The solar cell using the CTS thin film annealed at 570 °C exhibited an open-circuit voltage of 248 mV, a short-circuit current density of 33.5 mA/cm2, a fill factor of 0.439, and a conversion efficiency of 3.66%. [ABSTRACT FROM AUTHOR]

Cu2SnS3 is a promising compound for use as an absorber layer in thin film solar cells because it is made up of low-cost and abundant elements, and has a high optical absorption coefficient. However, the band gap energy of monoclinic Cu2SnS3 is less than the value required for absorber layers in single-junction solar cells. On the other hand, the band gap energy of Cu2SiS3 was reported to be approximately 2.5 eV, which is sufficiently large for this purpose. Therefore, in the present study, an attempt was made to synthesize Cu2Si x Sn1- xS3, which is a solid solution between Cu2SnS3 and Cu2SiS3. In X-ray diffraction patterns from the synthesized compounds, the diffraction peaks were found to shift to higher 2 θ values with increasing x, indicating a decrease in the lattice constants. In addition, the estimated band gap energy increased from 0.85 to 2.56 eV with increasing x. Cu2Si x Sn1- xS3 is therefore a potential candidate for use as the absorber layer in thin film solar cells because its band gap energy can be adjusted simply by varying its composition. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Cu2SnS3 is a promising compound for use as an absorber layer in thin film solar cells because it is made up of low-cost and abundant elements, and has a high optical absorption coefficient. However, the band gap energy of monoclinic Cu2SnS3 is less than the value required for absorber layers in single-junction solar cells. On the other hand, the band gap energy of Cu2SiS3 was reported to be approximately 2.5 eV, which is sufficiently large for this purpose. Therefore, in the present study, an attempt was made to synthesize Cu2Si x Sn1- xS3, which is a solid solution between Cu2SnS3 and Cu2SiS3. In X-ray diffraction patterns from the synthesized compounds, the diffraction peaks were found to shift to higher 2 θ values with increasing x, indicating a decrease in the lattice constants. In addition, the estimated band gap energy increased from 0.85 to 2.56 eV with increasing x. Cu2Si x Sn1- xS3 is therefore a potential candidate for use as the absorber layer in thin film solar cells because its band gap energy can be adjusted simply by varying its composition. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

The ternary compound semiconductor Cu2SnS3 (CTS) is formed from non-toxic materials that are abundant in Earth's crust and other low-cost elements. CTS has also been reported to a band gap energy range of 0.93-1.77 eV and an absorption coefficient of 1.0×104 cm-1. Consequently, CTS is a potential material for the p-type absorber layer of thin film solar cells. In this study, we examined the dependence of the optical, electrical and photovoltaic properties of CTS thin films on the Cu/Sn composition ratio. CTS thin films were fabricated by sulfurizing evaporated Cu-Sn precursors with different Cu/Sn composition ratios at 560 °C for 2 h in a N2 atmosphere and sulfur vapor. The Cu/Sn composition ratios of the sulfurized films were determined to be 1.6-2.5 by X-ray fluorescence. The solar cell comprising a CTS thin film with a Cu/Sn composition ratio of 1.77 exhibited the best performance among the cells examined, an open-circuit voltage of 242 mV, a short-circuit current density of 28.9 mA/cm2, a fill factor of 41.7% and a conversion efficiency of 2.92% were obtained. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Hydrogen atoms dissolve in Pd at densities up to one H atom per Pd, which provides higher atomic H density than in solid H. They are known to have large diffusion coefficient due to quantum tunneling. Torsional oscillator (TO) technique is employed to investigate the phases of H in Pd, which is known to show phase boundaries at the lowest T among metal-hydrogen (MH) systems. Specific heat measurements have been performed for PdH with x up to high H concentration specimens as well as studies of the resistivity study to establish the unique x− T phase diagram. We have, in addition, been performing TO experiments, in order to study the effect of atomic H intrusion and the dynamics in the PdH(D) system. The TO is a well-established, powerful instrument method to investigate superfluidity and quantum vortices of liquid He, especially in thin films, as well as dislocation dynamics in solids. In our TO experiments on PdH specimens have shown a resonance frequency shift for PdH, with 0.16≤ x≤0.75 at the lowest T's, which can be largely explained by the lattice deformation by H intrusion. This x dependent contribution has a smaller, additional change depending on x and T above ∼50 K. We will show the details of experimental data and discuss the correspondence to the phonon modes change and further possibility of studying occurrence of quantum phenomena for the hydrogen system. [ABSTRACT FROM AUTHOR]

Abstract: Cu2ZnSnS4 (CZTS) thin films were prepared by sulfurizing precursors deposited by electroplating. The precursors (Cu/Sn/Zn stacked layers) were deposited by electroplating sequentially onto Mo-coated glass substrates. Aqueous solutions containing copper sulfate for Cu plating, tin sulfate for Sn plating and zinc sulfate for Zn plating were used as the electrolytes. The precursors were sulfurized by annealing with sulfur at temperatures of 300, 400, 500 and 600°C in an N2 gas atmosphere. The X-ray diffraction peaks attributable to CZTS were detected in thin films sulfurized at temperatures above 400°C. A photovoltaic cell using a CZTS thin film produced by sulfurizing an electroplated Sn-rich precursor at 600°C exhibited an open-circuit voltage of 262mV, a short-circuit current of 9.85mA/cm2 and an efficiency of 0.98%. [Copyright &y& Elsevier]

Abstract: Stacked precursors of Cu, Sn, and Zn were fabricated on glass/Mo substrates by electron beam evaporation. Six kinds of precursors with different stacking sequences were prepared by sequential evaporation of Cu, Sn, and Zn with substrate heating. The precursors were sulfurized at temperatures of 560 °C for 2 h in an atmosphere of N2 +sulfur vapor to fabricate Cu2ZnSnS4 (CZTS) thin films for solar cells. The sulfurized films exhibited X-ray diffraction peaks attributable to CZTS. Solar cells using CZTS thin films prepared from six kinds of precursors were fabricated. As a result, the solar cell using a CZTS thin film produced by sulfurization of the Mo/Zn/Cu/Sn precursor exhibited an open-circuit voltage of 478 mV, a short-circuit current of 9.78 mA/cm2, a fill factor of 0.38, and a conversion efficiency of 1.79%. [Copyright &y& Elsevier]

(Cu,Ag)2SnS3 thin films and solar cells are prepared by sulfurization of KF/Sn/(Cu + Ag) stacked precursors in a sulfur and tin mixing atmosphere. Their properties are investigated. Stacked KF/Sn/(Cu + Ag) precursors are deposited on Mo/soda lime glass substrate by sequential evaporation of Cu + Ag, Sn elements, and KF. The molar ratios of the evaporation materials are held constant at (Cu + Ag):Sn = 1.0:0.6 and Ag/(Cu + Ag) = 0.05, and the KF/Cu molar ratio is changed from 0 to 0.05. The precursors are crystallized by annealing for 30 min at 570 °C in a sulfur and tin mixing atmosphere. The compositions are approximately constant, and the dependence of the composition ratio on the KF addition quantity is not observed. For all samples, the X‐ray diffraction patterns and the Raman spectra corresponding to CATS are obtained. The values of Voc increased with increasing KF/Cu molar ratio until KF/Cu = 0.03. The best solar cell in this study showed a Voc of 248 mV. [ABSTRACT FROM AUTHOR]

To enlarge the bandgap of Cu2SnS3 (CTS), Ag‐incorporating CTS thin films are successfully deposited by sulfurizing Ag‐Cu‐Sn precursors featuring various Ag contents and the constant Cu/Sn ratio of 1.75, which is the optimal value for CTS thin‐film solar cells. To control the Ag content of the films, the thickness of the Ag layers of the precursors is varied from 0 to 200 nm, which corresponds to the Ag/(Ag + Cu) ratio of the films varying from 0 to 0.32. The films featuring Ag/(Ag + Cu) ratios smaller than 0.16 are solid solutions of CTS and Ag2SnS3, that is, (Cu,Ag)2SnS3 (CATS), while the film featuring the Ag/(Ag + Cu) ratio of 0.32 appears to be a mixture of CATS and Ag‐Sn‐S related crystals, such as Ag8SnS6. The grain size and bandgap increase as the Ag/(Ag + Cu) ratio increases up to 0.16. The highest power conversion efficiency (PCE) of 3.6% is obtained for the cell featuring the Ag/(Ag + Cu) ratio of 0.08. The highest open cell voltage (VOC) for the CATS thin‐film solar cells is obtained to be 0.284 mV. However, the improvement in PCE is attributed to the increase in the short‐circuit current density and fill factor of the cell rather than the increase in VOC. [ABSTRACT FROM AUTHOR]