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We have been developing nanosized graphene, called graphene flower, as a material that induces coherent scattering very cold neutrons. Previous experiments have found that the seed part of the graphene flower is more effective than the petal part in increasing the coherent scattering. Based on these results, we found that further modification of the graphene flower to increase the seed portion increased the total cross-section, although it did not reach the level of nanodiamonds. [ABSTRACT FROM AUTHOR]

The Cu (ln1‐xGax)Se2 (CIGS) solar cell technology is a potentially high‐efficient approach with unique properties compared with silicon photovoltaic, like flexible lightweight substrates and different colored designs. So far, the full potential of the transparent conductive oxide layers has not been exploited yet as no front contacts are applied, resulting in significant losses from the cell‐to‐module level. In this study, Ag front contacts are applied by parallel dispensing onto indium tin oxide layers of silicon heterojunction substrates and CIGS substrates. Subsequently, a thermally curing process is carried out to form the conductive contacts. The curing conditions are varied between 200°C ≥ Tc ≥ 100°C combined with 20 min ≥ tc ≥ 1.5 min. The study aims to determine the curing parameters enabling low‐resistivity contacts by using low‐temperature curing Ag paste and ultralow‐temperature curing Ag paste. The lateral electrode resistance and the contact resistivity of printed electrodes are measured. The results of simultaneous thermogravimetry‐differential scanning calorimetry (pastes) and microstructure analysis of printed electrodes are used to explain the electrical parameters of the printed electrodes. In general, higher curing temperatures and longer curing durations encourage the sintering and densification process of the applied electrodes resulting in low‐resistivity contacts. Contact resistivities below ρc,TLM < 5 mΩ·cm2 and lateral electrode resistance of Rlateral ≥ 17 Ω m−1 are obtained for different paste systems. However, optimal curing conditions of low‐temperature curing pastes can cause thermal damage to the CIGS device. Therefore, ultralow‐temperature curing pastes seem to be promising candidates for front contact metallization of CIGS substrates. [ABSTRACT FROM AUTHOR]

It is proposed that nanosized graphene aggregation could facilitate coherent neutron scattering under particle size conditions similar to nanodiamonds to enhance neutron intensity below cold neutrons. Using the RIKEN accelerator-driven compact neutron source and iMATERIA at J-PARC, we performed neutron measurement experiments, total neutron cross-section and small-angle neutron scattering on nanosized graphene aggregation. For the first time, the measured data revealed that nanosized graphene aggregation increased the total neutron cross-sections and small-angle scattering in the cold neutron energy region. This is most likely due to coherent scattering, resulting in higher neutron intensities, similar to nanodiamonds. [ABSTRACT FROM AUTHOR]

Within this work, first bifacial silicon heterojunction solar cells with rotary screen printed front‐ and rear‐side metallization are demonstrated. The high‐throughput metallization process is carried out using an innovative rotary printing demonstrator machine with short process cycle times down to 0.65 s cell−1. Furthermore, a very low total silver consumption of only 6–9 mg Wp−1 for the fully metallized bifacial silicon heterojunction solar cells is demonstrated. Using a newly developed screen simulation approach, the utilized fine line rotary and flatbed screens are analyzed regarding their suitability for fine line metallization and verified using in‐depth analysis of the geometrical and electrical properties of printed and cured metallization. The best group of fully rotary screen printed cells obtains a mean conversion efficiency of ηRSP,avg = 21.7% which is close to the flatbed screen printed reference group with ηFSP,avg = 22.1%. Using a hybrid approach with a rotary screen printed grid on the rear side and flatbed screen printed grid on the front side, a mean conversion efficiency of ηhyb,avg = 22.0% is obtained with a very low total silver consumption of only 9 mg Wp. [ABSTRACT FROM AUTHOR]

The magnetic characteristics of Co-based alloy media made on amorphous carbon substrates were investigated using x-ray diffraction and transmission electron microscopy. The results showed that the material had superior coercivity as compared to those made on conventional NiP/Al substrates. In addition, excellent adhesion performance, attributed to the formation of a Cr-C compound at the interface, was observed.

We have successfully fabricated a filament-less X-ray tube using a graphene flower cloth (GFC) field emission cathode. The GFC has numerous nanoprotrusions formed by self-standing graphene structures. The field emission current and the field enhancement factor β were 500 µA and 5600, respectively. The stability of voltage defined as a variance coefficient (σ/mean) of voltage was calculated to be 0.04% while maintaining the X-ray tube current of 300 µA. We applied our X-ray tube with the GFC field emitter to the X-ray fluorescence (XRF) analysis of stainless steel. [ABSTRACT FROM AUTHOR]

In the field of silicon heterojunction (SHJ) solar cells, great successes on improving production processes have been achieved in the last years, however further improvements in the case of metallization are required to obtain higher market share. Therefore, lower Ag laydowns and higher process throughput are demanded. This study presents the impact of filament stretching on Ag-electrode shapes and laydown during temperature-controlled micro-extrusion, known as parallel dispensing. Dispensed metal grids ensure higher cell performances than screen-printed grids. It has been discovered that the maximum use of filament stretching benefits the solar cell efficiency due to narrower Ag-electrodes and less silver consumption. We have shown a low Ag laydown per 157.35 mm line of m Ag = 0.27 mg electrode-1 in average. An efficiency gain of Δη A = + 0.26% abs. has been demonstrated by the maximum usage of filament stretching. Further, a novel parameter that values the effectiveness of silver usage and enables the comparison between different printing processes has been introduced. We have demonstrated that silver is used more effectively by up to +74% rel. when the low-temperature curing paste is dispensed compared to screen printing because dispensed electrodes show an almost perfectly homogeneous shape. • Temperature-controlled filament stretching phenomenon during micro-extrusion obtains higher solar cell performances and higher throughput-rates. • Filament stretching phenomenon is process-specific and paste-specific. • Novel parameter is introduced to value the effectiveness of silver usage in printed structures. • Silver is used more effectively in dispensed lines than in screen-printed lines. [ABSTRACT FROM AUTHOR]

It is proposed that nanosized graphene aggregation could facilitate coherent neutron scattering under particle size conditions similar to nanodiamonds to enhance neutron intensity below cold neutrons. Using the RIKEN accelerator-driven compact neutron source and iMATERIA at J-PARC, we performed neutron measurement experiments, total neutron cross-section and small-angle neutron scattering on nanosized graphene aggregation. For the first time, the measured data revealed that nanosized graphene aggregation increased the total neutron cross-sections and small-angle scattering in the cold neutron energy region. This is most likely due to coherent scattering, resulting in higher neutron intensities, similar to nanodiamonds.