Electrochemical doping of mesoporous silicon with Er: The effect of the current intensity

Guido Mula*, Elisa Pinna, Andrea Falqui, Roberta Ruffilli, Simonetta Palmas, Michele Mascia

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

There is an ongoing intense research for cost-effective Er-doped Si-based light-emitting devices at the 1.5 μm wavelength. The efficient electrochemical Er-doping of porous silicon for this purpose requires a good understanding of the phenomena involved, since those taking place at the pores inner surface control the doping process. However, almost no attention has been given, to date, to the relevant effects of the current intensity onto the doping results. In this work, the effect of the current intensity on the doping process is explored by means of electrochemical impedance spectroscopy, optical reflectivity and energy dispersive spectrometry via scanning electron microscopy. The combined analysis of all results strongly suggests that the formation of a gel-like Er ethanolate, unaffected by changes in the sample thickness, occurs from the very first stages of the doping process. Moreover, while for constant current doping processes we show that, under any given doping condition, the doping level is proportional to the transferred charge, we demonstrate that performing the doping process using different current intensities may lead to dramatically different results.

Original languageEnglish (US)
Pages (from-to)252-257
Number of pages6
JournalApplied Surface Science
Volume311
DOIs
StatePublished - Aug 30 2014

Keywords

  • Electrochemical impedance spectroscopy
  • Er doping
  • Porous silicon

ASJC Scopus subject areas

  • Surfaces, Coatings and Films

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