Solar-grade silicon powder prepared by combining combustion synthesis with hydrometallurgy

Efficient Fabrication of Nanoporous Si and Si/Ge Enabled by a Heat Scavenger in Magnesiothermic Reactions

“…The dramatic morphological change after the MRR suggests a much higher local reaction temperature than the set temperature of 650°C. It was reported that the measured temperature in a MRR could reach 1720°C31. In contrast to Bulk-Si, with the introduction of NaCl, the cylindrical architectural features of diatom particles were partially maintained in Nano-Si (Fig.…”

Low-cost solar grade silicon powder through iterative gettering of thermally treated porous silicon

“…It has reported that HF can react with the oxide film and react with impurities further to enhance the purification effect. In addition, HF can react with inter-granular phases containing impurities in MG-Si, such as Fe-Si-Ti and Si-Fe, which cannot react with other acids as HCl and HNO3 [13][14][15]. Therefore and after thermal annealing, we used a diluted HF acid to remove the PS layer with the trapped impurities.…”

“…Therefore and in order to overcome this problem, many researchers have reported that purity improving of MG-Si can be achieved by (i) thermal decomposition of trichlorosilane at 1100 • C on a heated silicon rod placed inside a deposition chamber (chemical relation 1) [4][5][6][7][8][9][10][11][12][13][14][15][16][17]. This process, which was developed in the late fifties, is commonly referred to as the Siemens process with reference to the company that carried out its early development, (ii) decomposition of monosilane on a heated silicon rod inside a closed deposition chamber (chemical relation 2).…”

Porous Silicon Formation by Porous Silica Reduction

“…Examination of the literature (Bao et al 2007;Richman et al 2008;Hai et al 2009;Ibisate et al 2009;Won et al 2009Won et al , 2011Yu et al 2010;Zhu et al 2010Yermekova et al 2010;Chen et al 2011aChen et al , b, 2012aChen et al , b, 2013a Gallego-Gomez et al 2011;Gao et al 2011;Guo et al 2011;Jia et al 2011;Lu et al 2011;Pallavidino et al 2011;Zhang and Huang 2011;Batchelor et al 2012;Fang et al 2012;Shen et al 2012Shen et al , 2013Tao et al 2012a, b;Wang et al 2012;Yoo et al 2012;Huachao et al 2013;Jung et al 2013;Du et al 2013;Hong et al 2013;Jiang et al 2013;Lee et al 2013;Liu et al 2013;Luo et al 2013;Ma et al 2013;Meekins et al 2013;Wen et al 2013;Xing et al 2013a, b;Yoo et al 2013;Yu et al 2013;Yue et al 2013;Xia et al 2014) reveals that all three classes of porosity (see handbook chapters on ▶ Macroporous Silicon, ▶ Mesoporous Silicon, and ▶ Microporous Silicon) are achievable with magnesiothermic reduction, as are extremely high surface area structur...…”