Nanoscale morphology tuning of mesoporous Ge: electrochemical mechanisms

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• 作者：Sergii Tutashkonko^a ; ^b ; ^{sergii.tutashkonko@usherbrooke.ca" class="auth_mail" title="E-mail the corresponding author} ; Sergei Alekseev^c ; ^{alekseev@univ.kiev.ua" class="auth_mail" title="E-mail the corresponding author} ; Tetyana Nychyporuk^b ; ^{tetyana.nychyporuk@insa-lyon.fr" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Bipolar electrochemical etching ; Porous germanium ; Mesoporous materials ; Morphology
• 刊名：Electrochimica Acta
• 出版年：2015
• 出版时间：20 October 2015
• 年：2015
• 卷：180
• 期：Complete
• 页码：545-554
• 全文大小：4765 K

文摘

The extended analysis of influence of the surface hydrogen passivation degree on morphology of mesoporous Ge (PGe) formed by Bipolar Electrochemical Etching technique is reported. It is shown that the high degree of the surface passivation results in formation of the isotropic sponge-like PGe layers, whereas at low degree of the surface passivation the crystallographic “pine-tree-like” pores are obtained. The intermediate passivation results in the “fish-bone” morphology. It should be noted that the last two morphologies were never obtained before and are unique to mesoporous Ge. The electrochemical reactions taking place on Ge during BEE process are identified by analyzing the evolution of the surface potential during the BEE process; the results were interpreted similarly to the cyclic voltametry data. Finally, a general electrochemical model describing the pore formation with different morphologies depending on the surface passivation degree is introduced.