Electrodeposition of germanium from supercritical fluids.
Electrodeposition of germanium from supercritical fluids.
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DOI：
10.1039/c1cp22555c
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发表时间：
2012-01
期刊：
影响因子：
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通讯作者：
Jie Ke;P. Bartlett;David C Cook;T. Easun;M. George;W. Levason;G. Reid;D. Smith;Wenta Su;Wenjian Zhang
中科院分区：
文献类型：
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作者：
Jie Ke;P. Bartlett;David C Cook;T. Easun;M. George;W. Levason;G. Reid;D. Smith;Wenta Su;Wenjian Zhang
研究了几种Ge(II)和Ge(IV)化合物作为电沉积剂，用于从液体CH(3)CN和CH(2)F(2)以及含有共溶剂CH(3)CN(SCCO(2))和超临界CH(2)F(2)(SCCH(2)F(2))的超临界CO(2)中电沉积Ge。对于Ge(II)试剂，最有希望的结果是使用[Nbu(N)(4)][GeCl(3)]。然而，重现性较差，还原电流明显小于估计的传质极限值。在CH(3)CN和含CH(3)CN的超临界CO(2)中，[NbU(N)(4)][GeCl3]可在高阴极电位下沉积含Ge薄膜，但在所有情况下都受到C、O、F和Cl的严重污染。在液体CH(2)F(2)和超临界CH(2)F(2)中使用GeCl(4)得到了更有希望的结果。在这种情况下，还原电流与传质限制还原是一致的，体电沉积生成了非晶态Ge薄膜。X射线光电子能谱(XPS)表征表明，低水平的O、F和C存在，XPS证实了Ge和Ge氧化物的存在，拉曼光谱表明，用来获得拉曼测量的激光可以使沉积的非晶态Ge结晶。
Several Ge(II) and Ge(IV) compounds were investigated as possible reagents for the electrodeposition of Ge from liquid CH(3)CN and CH(2)F(2) and supercritical CO(2) containing as a co-solvent CH(3)CN (scCO(2)) and supercritical CH(2)F(2) (scCH(2)F(2)). For Ge(II) reagents the most promising results were obtained using [NBu(n)(4)][GeCl(3)]. However the reproducibility was poor and the reduction currents were significantly less than the estimated mass transport limited values. Deposition of Ge containing films was possible at high cathodic potential from [NBu(n)(4)][GeCl(3)] in liquid CH(3)CN and supercritical CO(2) containing CH(3)CN but in all cases they were heavily contaminated by C, O, F and Cl. Much more promising results were obtained using GeCl(4) in liquid CH(2)F(2) and supercritical CH(2)F(2). In this case the reduction currents were consistent with mass transport limited reduction and bulk electrodeposition produced amorphous films of Ge. Characterisation by XPS showed the presence of low levels of O, F and C, XPS confirmed the presence of Ge together with germanium oxides, and Raman spectroscopy showed that the as deposited amorphous Ge could be crystallised by the laser used in obtaining the Raman measurements.