Study of photo-oxidized n-type textured silicon surface through electrochemical impedance spectroscopy
- Resource Type
- Authors
- Pierre-Philippe Grand; Arnaud Etcheberry; Cécile Molto; Anne-Marie Goncalves
- Source
- Journal of The Electrochemical Society
Journal of The Electrochemical Society, Electrochemical Society, 2020, 167 (14), ⟨10.1149/1945-7111/abc0a6⟩
- Subject
- Materials science
Silicon
Renewable Energy, Sustainability and the Environment
business.industry
020209 energy
chemistry.chemical_element
02 engineering and technology
[CHIM.MATE]Chemical Sciences/Material chemistry
Overpotential
Condensed Matter Physics
Surfaces, Coatings and Films
Electronic, Optical and Magnetic Materials
Dielectric spectroscopy
chemistry
Etching (microfabrication)
Ellipsometry
0202 electrical engineering, electronic engineering, information engineering
Materials Chemistry
Electrochemistry
Optoelectronics
Crystalline silicon
Thin film
business
Silicon oxide
- Language
- English
- ISSN
- 0013-4651
1945-7111
International audience; For crystalline silicon (c-Si) solar cells, it is useful to measure accurately the thickness of silicon oxide (SiOx) layer presents on textured c-Si surface to further adapt the fluoride-based etching treatment. Common techniques used to characterize thin films thicknesses, such as ellipsometry or profilometry, are however not suitable for highly textured surfaces. In this work, a methodology based on Electrochemical Impedance Spectroscopy (EIS) has been developed to determine the thickness of anodic SiOx on n-type textured c-Si surface. EIS measurements have been carried out on bare c-Si surface as well as on c-Si surface with various anodic SiOx thicknesses grown by photo-oxidation. The as-obtained Nyquist and Bode diagrams enabled to plot the related Mott-Schottky curves and determine the corresponding flatband potentials (Vfb). A reference standard graph giving the anodic SiOx thickness according to measured Vfb has been therefore established. A shift of Mott-Schottky curves towards higher potential values with increased anodic SiOx thickness has been shown and explained. Mott-Schottky curves of photo-oxidized silicon surfaces have demonstrated a particular shape related to the different behaviors of Si/SiOx/electrolyte device depending on the applied overpotential. These results have been used to study the etching rate of anodic SiOx in NaHF2 fluoride media.