Tunable Nanostructuration of Si by MACE with Pt nanoparticles under an applied external bias
Résumé
We present a study on metal assisted chemical etching of p-type c-Si with Pt nanoparticles, performed under controlled polarization of the Si sample in a 3-electrodes electrochemical setup. OCP measurements combined with impedance spectroscopy and cyclic voltammetry allow to give physical insights in the MACE process. In addition, the application of an external polarization during etching results in a straightforward control of the pore morphology, ranging from straight mesopores to cone-shaped macropores as the Si sample is positively biased. The latter morphology leads to a reduction of the surface reflectivity below 5% which compares favorably with state of the art texturization techniques for Si solar cells.