**2.2 Photoluminescence of porous silicon layers**

*Solar Cells - Theory, Materials and Recent Advances*

**2. Photoluminescence study**

applied on the surface of the sample.

range [10–300 K].

**2.1 Experimental details**

temperature studies) (**Figure 1**).

optical characterization technique for nanomaterials.

substrate with a resistivity of 0.001–0.02 Ω cm.

current density, and anodization time) [26]. The present study conclusively suggested that in order to prepare porous silicon samples, we need to determine the optimal conditions that lead to increase the optical efficiency. Herein, we need to study the correlation between the results extracted from the PL analysis and those obtained by ellipsometry. The study of the evolution of the intensities of the emission spectra obtained by the measurement of PL as a function of the porosity and the thickness determined by the ellipsometry of the layers for silicon substrates oriented P-100 of low resistivity is made to precisely clarify the evolution of optical parameters.

The PL measurements were carried out by a solid laser 447 nm and detected through a Jobin Yvon 250-mm HR mono-chromator, with a GaAs photomultiplier associated to standard lock-in technique. Of note, the laser power of 7.66 mW was

The optical characterization used in our work is based on "the radiationmatter interaction"; it tells us about the optical properties of the material. Photoluminescence spectroscopy is widely used to study the electronic structure of materials and the processes of radiative recombinations. It is a nondestructive

In this part, using photoluminescence (PL) spectroscopy, we will determine the optical properties of porous silicon samples produced by electrochemical anodization. First, we analyze the PL spectra of SiP at room temperature. Second, we study the variation of the intensity, and the integrated intensity of PL in the temperature

Serial of porous silicon samples were prepared of *p*-type (100)-oriented silicon

The experimental set-up consists first of all of a pulsed laser, the emission wavelength of which can be changed. The laser we have allows us to take measurements with an excitation of 447 nm. The laser beam is then conveyed to the sample by sets of mirrors. The sample is on a sample holder that can be placed in a cryostat (for low

**110**

**Figure 1.**

*Experimental device used for the measurement of photoluminescence.*
