**3. Results and discussion**

Usually "hybrid materials" are used to describe two conjugated components that are chemically different. Here, we use it to define the molecular junction that are obtained after grafting an organic molecule to Si. An example for this is illustrated in **Figure 4**, where alkyl molecules are chemically attached to Si NW via Si▬C bonds [27].

#### **3.1 Organic functionalization via chlorination/alkylation**

The method provides oxide-free Si and is consistent By chlorination/alkylation as shown in **Figure 5**. After hydrogenation and for the first step, we get Cl bonds by immersing the Si NWs sample in a saturated PCl5 solution. In the second step, we

*Heterojunction-Based Hybrid Silicon Nanowires Solar Cell DOI: http://dx.doi.org/10.5772/intechopen.84794*

**Figure 4.**

*Hybrid Si NW: the organic molecules (alkyl as example) are chemically connected to Si NW by covalent bonds Si*▬*C.*

**Figure 5.**

*Scheme illustrating the functionalization of Si NWs through the two-step chlorination/alkylation process.*

**Figure 6.** *Schematic diagram of SiOx/Si interface.*

convert the chlorine atoms by Grignard reaction to organic molecules. The organic molecule (alkyl as an example) will be attached normally to the surface by siliconalkyl surface bonds, i.e., Si▬C bonds [30, 34].
