Importance of the Electrolyte in Obtaining Porous Silicon and How It Modifies the Optical and Structural Proprieties: Optical and Microstructural Investigation

Abstract EN

The effect of using different electrolytes in the physical and optical properties of porous silicon was studied.

To do this porous silicon (PS) samples photoluminescent in the visible range from (100) oriented n-type crystalline silicon prepared by anodic etching were obtained.

The first electrolyte was composed of a mixture of hydrofluoric acid (HF) and ethanol (CH3-CH2-OH) in a ratio of 1 : 2, respectively.

The second was composed of hydrofluoric acid (HF), ethanol (CH3-CH2-OH), and hydrogen peroxide (H2O2) in a ratio of 1 : 1 : 2, respectively.

Raman scattering, photoluminescence (PL), gravimetry, scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS) measurements on the PSL were carried out.

Raman scattering showed that the disorder in the samples obtained with H2O2 is greater than in the samples obtained without this.

The PL from PS increased in intensity with the incremental change in the anodization time and showed a blueshift.

The blueshift of PL is consistent with the reduction in size of the silicon nanocrystallites.

The sizes of nanocrystals were estimated to be 3.08, 2.6, and 2.28 nm.

The gravimetric analysis showed that the porosity increased with the incorporation of H2O2.

SEM images (morphological analysis) showed an incremental change in the quantity and in the porous size.