A spherical Si solar cell with a reflector cup was successfully fabricated by a dropping method at decompression state. In the dropping method, melted Si droplets were instilled at decompression state (0.5×105 Pa...A spherical Si solar cell with a reflector cup was successfully fabricated by a dropping method at decompression state. In the dropping method, melted Si droplets were instilled at decompression state (0.5×105 Pa) to reduce crystal growth rate, dominating crystal quality such as dislocation density in crystal grains. Spherical Si solar cells were fabricated using the spherical Si crystals with a diameter of 1 mm and then mounted on a reflector cup. The current-voltage measurement of the solar cell shows an energy conversion efficiency of 11.1% (short-circuit current density (Jsc): 24.7 mA·cm-2, open-circuit voltage: 601 mV, fill factor: 74.6%). Minority carrier diffusion length determined by surface photovoltage method was 98 μm. This value can be enhanced by the improvement of crystal quality of spherical Si crystals. These results demonstrate that spherical Si crystals fabricated by the dropping method has a great potential for substrate material of high-efficiency and low-cost solar cells.展开更多
The density of Ni-Cr alloy in the mushy state has been measured using the modified sessile drop method. The density of Ni-Cr alloy in the mushy state was found to decrease with increasing temperature and Cr concentrat...The density of Ni-Cr alloy in the mushy state has been measured using the modified sessile drop method. The density of Ni-Cr alloy in the mushy state was found to decrease with increasing temperature and Cr concentration in alloy. The molar volume of Ni-Cr alloy in the mushy state therefore increases with increasing the Cr concentration in alloy. The ratio of the difference of density divided by the temperature difference between liquidus and solidus temperatures decreases with increasing Cr concentration. The density of the alloy increased with the precipitation of a solid phase in alloy during the solidification process. The temperature dependence of the density of alloy in the mushy state was not linear but biquadratic.展开更多
基金This work was partly financially supported by NEDO.
文摘A spherical Si solar cell with a reflector cup was successfully fabricated by a dropping method at decompression state. In the dropping method, melted Si droplets were instilled at decompression state (0.5×105 Pa) to reduce crystal growth rate, dominating crystal quality such as dislocation density in crystal grains. Spherical Si solar cells were fabricated using the spherical Si crystals with a diameter of 1 mm and then mounted on a reflector cup. The current-voltage measurement of the solar cell shows an energy conversion efficiency of 11.1% (short-circuit current density (Jsc): 24.7 mA·cm-2, open-circuit voltage: 601 mV, fill factor: 74.6%). Minority carrier diffusion length determined by surface photovoltage method was 98 μm. This value can be enhanced by the improvement of crystal quality of spherical Si crystals. These results demonstrate that spherical Si crystals fabricated by the dropping method has a great potential for substrate material of high-efficiency and low-cost solar cells.
文摘The density of Ni-Cr alloy in the mushy state has been measured using the modified sessile drop method. The density of Ni-Cr alloy in the mushy state was found to decrease with increasing temperature and Cr concentration in alloy. The molar volume of Ni-Cr alloy in the mushy state therefore increases with increasing the Cr concentration in alloy. The ratio of the difference of density divided by the temperature difference between liquidus and solidus temperatures decreases with increasing Cr concentration. The density of the alloy increased with the precipitation of a solid phase in alloy during the solidification process. The temperature dependence of the density of alloy in the mushy state was not linear but biquadratic.
