title: Electrochemical differential photoacoustic cell to study in situ the growing process of porous materials.
abstract: In order to study in situ the growing process of porous materials, a new electrochemical differential photoacoustic cell (DPC) was developed. This system allows to obtain the thermal signals coming from the growing process of the pores without the external noise component. The DPC is a good system to growth porous silicon and study their growing process with reproducibility. The porous silicon samples were obtained by using electrochemical etching of (100) n-type silicon wafers with different nominal resistivity values in the range of 1-25 Omega cm. The samples were formed in a solution of hydrofluoric acid and ethanol having a composition ratio of 1:1 in volume with etching voltage of 10 V and an etching time of 2 min using back illumination provided by a laser beam with a wavelength of 808 nm. The porous samples were characterized by means of Raman microscopy, x-ray diffraction, and scanning electron microscopy. The crystallite sizes of the samples were obtained through the analysis of the micro-Raman spectra using a phonon confinement model, and the analysis of the x-ray diffractograms.
authors.affiliation: Departamento de Física, Universidad Nacional de Colombia-Sede Bogotá, Avenida Carrera 30 No. 45-03, Ciudad Universitaria, Bogotá, D.C., Colombia.
authors.forename: Adriana
authors.initials: A
authors.lastname: Gutiérrez
authors.forename: Jairo
authors.initials: J
authors.lastname: Giraldo
authors.forename: Rubén
authors.initials: R
authors.lastname: Velázquez-Hernández
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Mendoza-López
authors.forename: Diego G
authors.initials: DG
authors.lastname: Espinosa-Arbeláez
authors.forename: Alicia
authors.initials: A
authors.lastname: del Real
authors.forename: Mario E
authors.initials: ME
authors.lastname: Rodríguez-García