**3. Photon Management for Photovoltaics**

Photon management for photovoltaics (PV) is focused for increasing the solar absorbance of solar irradiance through some modification of the photovoltaic

**427**

**Figure 1.**

*[31] with permission).*

*Advanced Laser Processing towards Solar Cells Fabrication*

material. Very small sized (micrometer-sized) photovoltaic material (eg. silicon) spikes decrease geometric light trapping for reflection. The extent of geometric light trapping enhances optical path length. The light trapping depends on the height, spacing, and subtended angle although structures with large, graded density and the spike heights will not play for visible and near-IR light. Multiple reflection on the surface is the dominant effect of light trapping [26–30]. Treating the case of spikes subtending a cone angle of 42°, observed on a silicon surface after irradiation in pulsed-laser hyper doping and surface texturing as shown in **Figure 1a**. Incident light undergoes four reflections before escaping as illustrated in **Figure 1b** of the optical path of light incident on laser-textured silicon surfaces, with cones

There are also several ways to increase the performance in solar cells as reviewed

The novel technique of isotropic texturing of the multi-crystalline surface basically use acidic solution (such as HNO3–HF–CH3COOH) followed by a simple chemical treatment to make the surface more uniform in terms of roughness [31]. Due to high reflectivity of acid textured surface helps to improve the open circuit voltage but gives lower short circuit current of the multi-crystalline silicon (mc-Si)

The mechanically texturized structures created by anisotropic etching of monocrystalline silicon, resulted the first silicon solar cell to exceed 20% energy conversion efficiency at 1-sun illumination because of positive trend of improvement in

Texturing surface have been developed using the reactive ion etching (RIE) method, which is expected to form a low reflectance surface on various crystalline

*Pulsed-laser hyper doping and surface texturing, Cambridge (2001) (ref. R. Younkin, PhD dissertation, Harvard University), (a) scanning electron micrographs, (b) illustration of the optical path (adapted from* 

*DOI: http://dx.doi.org/10.5772/intechopen.94583*

subtending 42°.

solar cell [32].

in the following section.

**3.2 Mechanical grooving**

**3.3 Reactive ion etching (RIE)**

orientations of grains [34, 35].

the electronic quality of the c-Si substrates [33].

**3.1 Isotropic acidic texturing**

*Advanced Laser Processing towards Solar Cells Fabrication DOI: http://dx.doi.org/10.5772/intechopen.94583*

material. Very small sized (micrometer-sized) photovoltaic material (eg. silicon) spikes decrease geometric light trapping for reflection. The extent of geometric light trapping enhances optical path length. The light trapping depends on the height, spacing, and subtended angle although structures with large, graded density and the spike heights will not play for visible and near-IR light. Multiple reflection on the surface is the dominant effect of light trapping [26–30]. Treating the case of spikes subtending a cone angle of 42°, observed on a silicon surface after irradiation in pulsed-laser hyper doping and surface texturing as shown in **Figure 1a**. Incident light undergoes four reflections before escaping as illustrated in **Figure 1b** of the optical path of light incident on laser-textured silicon surfaces, with cones subtending 42°.

There are also several ways to increase the performance in solar cells as reviewed in the following section.
