Growth and Structural Characterization of Spherical Silicon Crystals Grown from Polysilicon

Abstract

The growth process for spherical silicon crystals using melting and recrystallization of polysilicon powder and polysilicon granules is investigated and the structural properties of the fabricated silicon spheres are characterized. The recrystallization conditions that influence the crystallinity of the spheres are studied. It is shown by means of defect delineation that crystalline structures are obtained when the melt is solidified at temperatures above 1400°C. The results of electron backscattering confirm the formation of singlegrain structures. When solidification takes place at temperatures below 1400°C, double-and multiple-grain structures start to form. The concentration of impurities during the recrystallization of the spheres, monitored by secondary-ion mass spectroscopy, show that the rate of impurity removal from the crystalline phase is much lower than predicted by segregation at the meltsolid interface, which is attributed to the nonequilibrium conditions in the solidification process.

Construction and characterization of spherical Si solar cells combined with SiC electric power inverter

“…Spherical Si solar cells can reduce the consumption of Si compared with the conventional crystal Si solar cells [12][13][14][15][16][17][18][19][20]. Flexible, light solar cells were also manufactured using silicon spheres with a diameter of ~1 mm with a pn junction [21].…”

44.4L: Late‐News Paper: Large Area Display Backplane Using Embedded Single‐Crystal Silicon Particles

“…These spheres have higher material quality than either amorphous-, nano-, or poly-crystalline Si [3,4]. The challenges associated with making such large crystal spheres are largely due to the internal stresses developed when cooling.…”

Construction and evaluation of photovoltaic power generation and power storage system using SiC field-effect transistor inverter

“…Consumption of Si can be reduced for the use of spherical Si solar cells, compared with conventional crystal Si solar cells [15][16][17][18][19][20][21][22][23][24]. Flexible and light solar cells were also manufactured using silicon spheres with a diameter of ~1 mm with a pn junction at the sphere surface [24][25][26][27].…”