title: Controlling the Er content of porous silicon using the doping current intensity.
abstract: The results of an investigation on the Er doping of porous silicon are presented. Electrochemical impedance spectroscopy, optical reflectivity, and spatially resolved energy dispersive spectroscopy (EDS) coupled to scanning electron microscopy measurements were used to investigate on the transient during the first stages of constant current Er doping. Depending on the applied current intensity, the voltage transient displays two very different behaviors, signature of two different chemical processes. The measurements show that, for equal transferred charge and identical porous silicon (PSi) layers, the applied current intensity also influences the final Er content. An interpretative model is proposed in order to describe the two distinct chemical processes. The results can be useful for a better control over the doping process.
  81.05.Rm; 82.45.Rr.
authors.affiliation: Dipartimento di Fisica, Cittadella Universitaria di Monserrato, Università degli Studi di Cagliari, S.P. 8 km 0.7, Monserrato, Cagliari 09042, Italy.
authors.forename: Guido
authors.initials: G
authors.lastname: Mula
authors.affiliation: Dipartimento di Fisica, Cittadella Universitaria di Monserrato, Università degli Studi di Cagliari, S.P. 8 km 0.7, Monserrato, Cagliari 09042, Italy.
authors.forename: Lucy
authors.initials: L
authors.lastname: Loddo
authors.affiliation: Dipartimento di Fisica, Cittadella Universitaria di Monserrato, Università degli Studi di Cagliari, S.P. 8 km 0.7, Monserrato, Cagliari 09042, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Pinna
authors.affiliation: Dipartimento di Fisica, Cittadella Universitaria di Monserrato, Università degli Studi di Cagliari, S.P. 8 km 0.7, Monserrato, Cagliari 09042, Italy.
authors.forename: Maria V
authors.initials: MV
authors.lastname: Tiddia
authors.affiliation: Dipartimento di Ingegneria Meccanica Chimica e dei Materiali, Università degli Studi di Cagliari, Piazza d'Armi, Cagliari 09123, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Mascia
authors.affiliation: Dipartimento di Ingegneria Meccanica Chimica e dei Materiali, Università degli Studi di Cagliari, Piazza d'Armi, Cagliari 09123, Italy.
authors.forename: Simonetta
authors.initials: S
authors.lastname: Palmas
authors.affiliation: Nanochemistry, Istituto Italiano di Tecnologia, Via Morego 30, Genova 16163, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Ruffilli
authors.affiliation: Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Jeddah, Kingdom of Saudi Arabia.
authors.forename: Andrea
authors.initials: A
authors.lastname: Falqui
keywords: Electrochemical impedance spectroscopy; Er doping; Porous Silicon; Reflectivity; Scanning electron microscopy