Section 2 Crystalline Si Cells

**109**

**Chapter 7**

Application

important interest in the photovoltaic field.

photoluminescence, spectroscopic ellipsometry

*Rahmouni Salah*

**Abstract**

**1. Introduction**

ellipsometry (SE).

Optical Study of Porous

Silicon Layers Produced

Electrochemically for Photovoltaic

In previous years, porous silicon is rapidly attracting increasing interest in various fields and has received a great deal of attention from researchers because of its potential use in a variety of industrial applications such as photovoltaic device applications. The present study conclusively suggested that in order to prepare porous silicon samples, we need to determine the optimal conditions that lead to the increase of the optical efficiency. Porous silicon layers were elaborated by the electrochemical etching method using doped -type ⟨100⟩-oriented silicon substrate. The photoluminescence (PL) and the spectroscopic ellipsometry (SE) measurements were used to calculate the physical and optical parameters (porosity, thickness) (refractive index and extinction coefficient). This study can give a very

**Keywords:** porous silicon, antireflective coating, electrochemical anodization,

Porous silicon has undergone many developments; it has a very wide field of application and has received a great deal of attention from researchers because of its potential use in a variety of industrial applications such as photovoltaic device applications [1–4], chemical and gas sensors [5–12], biosensors [13, 14], biomedical applications [15], micromachining [16–18], templates for micro- and nanofabrication [19–21], and solar cells and photoluminescence [1, 22, 23]. However, a very limited data of optoelectronic uses in this field are available [24, 25]. It is reported that the photoluminescence of porous silicon (PS) has achieved a largescale investigation, giving an explanation of the photoluminescence phenomenon with obtaining the optical properties of porous silicon, as well as determining its refractive index and the gap energy, which can be determined directly by the absorption measurement, or by a non-destructive technique called spectroscopic

However, the physical and optical properties could be studied. In addition, some of the physical phenomena are still poorly understood because of the strong relationship between the PS nanostructure and the elaboration conditions (HF concentration,
