In Situ Photoacoustic Study of Optical Properties of P-Type (111) Porous Silicon Thin Films
| Autor: | Cesar Isaza, C.F. Ramirez-Gutierrez, Mario E. Rodríguez-García, Ely Karina Anaya Rivera, Ivan Alonso Lujan-Cabrera |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Silicon reflectance General Chemical Engineering Analytical chemistry chemistry.chemical_element Physics::Optics 02 engineering and technology Substrate (electronics) Porous silicon 01 natural sciences Article Etching (microfabrication) 0103 physical sciences General Materials Science Thin film QD1-999 Photonic crystal 010302 applied physics refractive index cross section Anodizing 021001 nanoscience & nanotechnology Chemistry chemistry dispersion 0210 nano-technology Refractive index photonic crystal |
| Zdroj: | Nanomaterials Nanomaterials, Vol 11, Iss 1314, p 1314 (2021) Volume 11 Issue 5 |
| ISSN: | 2079-4991 |
| Popis: | Porous silicon (PSi) on p++-type (111) silicon substrate has been fabricated by electronically etching method in hydrofluoric acid (HF) media from 5 to 110 mA/cm2 of anodizing current density. The problem of determining the optical properties of (111) PSi is board through implementing a photoacoustic (PA) technique coupled to an electrochemical cell for real-time monitoring of the formation of porous silicon thin films. PA amplitude allows the calculation of the real part of the films refractive index and porosity using the reflectance self-modulation due to the interference effect between the PSi film and the substrate that produces a periodic PA amplitude. The optical properties are studied from specular reflectance measurements fitted through genetic algorithms, transfer matrix method (TMM), and the effective medium theory, where the Maxwell Garnett (MG), Bruggeman (BR), and Looyenga (LLL) models were tested to determine the most suitable for pore geometry and compared with the in situ PA method. It was found that (111) PSi exhibit a branched pore geometry producing optical anisotropy and high scattering films. |
| Databáze: | OpenAIRE |
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