One-pot Ag-assisted chemical etching (SACE) of silicon provides an effective, simple way to obtain Si nanowires (NWs) of potential interest for technological applications ranging from photovoltaics to thermoelectricity. The detailed mechanism ruling the process has not been yet fully elucidated, however. In this paper we report the results of an extended analysis of the interplay among doping level and type of silicon, nanowire nanomorphology and the parameters controlling the chemistry of the etching process. We provide evidence that the SACE mechanism entirely occurs at the interface between the etching solution and the Si substrate as a result of Si extrusion by sinking self-propelled Ag particles. Also, a rationale is advanced to explain the reported formation of (partially) porous NWs at high doping levels in both p- and n-type Si. A model not relying on the asserted formation of potential barriers enables to recover full consistency between SACE electrochemistry and the mechanism of formation of porous silicon in electrochemical cells.

Magagna, S., Narducci, D., Alfonso, C., Dimaggio, E., Pennelli, G., Charaï, A. (2020). On the mechanism ruling the morphology of silicon nanowires obtained by one-pot metal-assisted chemical etching. NANOTECHNOLOGY, 31(40) [10.1088/1361-6528/ab9b47].

On the mechanism ruling the morphology of silicon nanowires obtained by one-pot metal-assisted chemical etching

Magagna, Stefano
Membro del Collaboration Group
;
Narducci, Dario
Membro del Collaboration Group
;
2020

Abstract

One-pot Ag-assisted chemical etching (SACE) of silicon provides an effective, simple way to obtain Si nanowires (NWs) of potential interest for technological applications ranging from photovoltaics to thermoelectricity. The detailed mechanism ruling the process has not been yet fully elucidated, however. In this paper we report the results of an extended analysis of the interplay among doping level and type of silicon, nanowire nanomorphology and the parameters controlling the chemistry of the etching process. We provide evidence that the SACE mechanism entirely occurs at the interface between the etching solution and the Si substrate as a result of Si extrusion by sinking self-propelled Ag particles. Also, a rationale is advanced to explain the reported formation of (partially) porous NWs at high doping levels in both p- and n-type Si. A model not relying on the asserted formation of potential barriers enables to recover full consistency between SACE electrochemistry and the mechanism of formation of porous silicon in electrochemical cells.
Articolo in rivista - Articolo scientifico
Metal-Assisted Chemical Etching; Silicon; Nanowires
English
2020
31
40
404002
none
Magagna, S., Narducci, D., Alfonso, C., Dimaggio, E., Pennelli, G., Charaï, A. (2020). On the mechanism ruling the morphology of silicon nanowires obtained by one-pot metal-assisted chemical etching. NANOTECHNOLOGY, 31(40) [10.1088/1361-6528/ab9b47].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/282286
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