Influence of Etching Current Density on the Structural and Optical Properties of Porous Silicon Films Developed For Photovoltaic Applications

Optical parameters of porous silicon films of doped 100-oriented silicon substrate fabricated by electrochemical etching are investigated. The photoluminescence and ellipsometry measurements were realized under the effect of etching current densities and contact times. The ellipsometry is simulated using a model of multilayer structures that allows the determination of the thickness, refractive index, penetration factor, extinction coefficient, absorption coefficient, and porosity of the silicon (PS) layer. Our results have shown that agreement is obtained between the PL measurements, represented by the integrated PL intensity, together with the FTIR and SEM measurements, represented by the thickness and the porosity of the porous layers, for etching time and varying current density. The absorption coefficient decreased as a function of the current density value with increasing porosity, and the penetration factor is an increasing function with current density. We also note that the data presented in this work are more promising for the development of layers for photovoltaic applications.

Automated summary

The optical properties of porous silicon films on doped 100-oriented silicon substrates prepared by electrochemical etching were studied. Photoluminescence and ellipsometry measurements were performed to investigate the effects of etching current densities and contact times. The results showed that the ellipsometry measurements were in good agreement with the photoluminescence intensity, thickness, and porosity obtained from FTIR and SEM measurements. The absorption coefficient decreased with increasing porosity, while the penetration factor increased with increasing current density. The data presented in this study are promising for the development of photovoltaic applications.