**1. Introduction**

Metal nanowires (MNWs) such as silver, copper, nickel, and gold nanowires have a large value of conductivity and transparency. It could be replaced by ITO, but yet these MNWs networks or grids or meshes need more research and development (R&D) consideration from the scientific community in order to make them proficient for successful applications in recent transparent electrodes (TEs) industry. This can be realized by synthesizing MNWs using simple and economic solution-phase techniques and then transferring these MNWs into coating source. That coating source will be used to coat a transparent substrate with a film of MNWs. Even though silver (Ag) (approximately \$766/kg) is costly than indium (In) (approximately \$601/kg) [1–3], but these silver nanowires (Ag-NWs) can be synthesized using roll-to-roll inexpensive solution coating methods. Because of their economic processing expenditure, the stipulation of Ag-NWs is rising for their appliance in touch sensors as TEs.

Some researchers have reported the scalable synthesis of Cu-NWs via solution coating techniques to make TEs with performance equivalent to ITO [4]. This is inspired by the insight of combining the low cost and simple deposition techniques of Cu-NWs; since Cu is more copious (~1000 times) and less expensive (100 times) than Ag or In.

Recently, Cu-NWs have presented the transmittance of ~96% and sheet resistance of ~100 Ω/sq. However, a major challenge for the successful application of Cu-NWs as TEs is to protect it from oxidation while maintaining its performance equivalent to ITO. As discussed above, here are various substitutes available for ITO, but the successful candidate is MNWs networks or meshes which are capable of showing performance equivalent to ITO due to ease of synthesis via solution coating techniques. Moreover, MNWs networks or meshes are more flexible and stretchable as compared to ITO [5]. These nanowires based transparent conducting electrodes based devices or individual metal nanowires based nanodevices will be used under the harsh environment such as the upper space radiation environment. Therefore, radiation effects study on these metal nanowires is important.

Damage to the structure of nanomaterials on contact to high energy ion beams has been the general perceptive, but recent research has made known it to be as a tool to tailor electronic, optical and field emission properties and to change the structure of nanomaterials in an excellent controllable way [6–10].

Ion beam radiation effects on MNWs have been recently studied [11–16]. In literature, protons ions irradiated bismuth nanowires (Bi-NWs) were reported and found that electrical conductivity decreased with an increase in protons beam fluence due to crystal structural damage, while see-back coefficient remained unaffected. It was concluded that the crystal structure of Bi-NWs destroyed under protons irradiation, which consequently decreased mobility, whereas carrier concentration was unchanged [17]. Molecular dynamics simulations study was reported to examine a damage profile in Cu-NWs that occurred during exposure to ions beam having low energies [18]. A similar study has been done employing molecular dynamics simulations and found that mechanical properties of Cu-NWs are devastated due to ion beam irradiation [19]. Moreover, enhancement in conductivity of Cu-NWs is reported after their irradiation with gamma rays [20]. In addition, Co-NWs were irradiated with gallium (Ga<sup>+</sup> ) Ions and found that the propagation field of domain walls is modified within the magnetic channels [21]. Moreover, interconnections through welding of various nanomaterials have also been built using different ion beams, which lead to enhance electrical conductivity [22–24].

To understand ion implantation effects on nanomaterials clearly, one must be aware of radiations and basics of ion solid interaction mechanisms. However, the unfavorable outcomes of radiations are termed as radiation-induced damage. In the next section, the general effects of irradiation on materials are discussed briefly.

### **2. Effects of ion implantation on materials**

In ion beam implantation process principle is based on the extraction of beams of ions from the source and accelerate at a specific voltage often lies between 50 and 250 keV with a desired energy up to 10 MeV before transportation and impingement on the target or substrate [25]. The impingement causes the ions to interact with the specimen surface in which some are embedded in the specimen while some are scattered. Ion implantation is ingenious in surface modification of materials while retaining their bulk properties [25–27]. The beam implantation process, which can be static, broad and unidirectional, can either improve or cause a defect in the properties of materials like toughness, fatigue, wear, hardness, friction, dielectric, magnetic, electronic, resistive and superconductivity [25]. These effects are subjected to the applications of the prepared materials. This implantation can be done in materials like ceramics, insulators, semiconductors, metals, alloys and polymers. The magnitude of the defect caused in the materials depends majorly on

**5**

**Figure 1.**

*(reuse after copyrights permission) [30].*

*Ion Implantation in Metal Nanowires*

*DOI: http://dx.doi.org/10.5772/intechopen.92328*

the crystal structure of the specimen [25–28].

controlled with the effect of ion implantation [26–28].

growth of the inherent defect state of the sample [24, 29].

**2.1 Ion beam-induced morphological changes in silver nanowires**

*(a) Un-implanted Ag-NWs, (b) 5 MeV carbon ions at the dose of 5 × 1014 ions/cm2*

*, and (c, d) 1 × 1016 ions/cm2*

The morphology shows long-shaped Ag-NWs. After 5 MeV, carbon ions

the mass of the incoming ion to the specimen, the accelerating voltage used for the beam, the thermal properties of the point defects confining the cascade region and

The most characteristic feature in ion implantation of materials is the generation of lattice disordered, which can be enhanced using low dose energy of heavy ions. In optical materials, ion implantation often stimulates luminescence to analyze the purity and point defects in the materials. Also, electro-optic, birefringence, refractive index, optical waveguide, reflectivity absorption band, thermoluminescence, electrical conductivity, piezoelectric, an optoelectric, and acoustic wave can be

The ion implantation effect also creates luminescence in some crystal materials. The luminesces observed during ion beam implantation in materials give information on the dynamic defect states owing to the transient features by the passage of ions that are difficult to excite. The defects observed can then be sensed by ion beam-induced luminescence and give information about the decay, impurities, or

The morphological image of un-implanted Ag-NWs is presented in **Figure 1(a)**.

### *Ion Implantation in Metal Nanowires DOI: http://dx.doi.org/10.5772/intechopen.92328*

*Ion Beam Techniques and Applications*

Recently, Cu-NWs have presented the transmittance of ~96% and sheet resistance of ~100 Ω/sq. However, a major challenge for the successful application of Cu-NWs as TEs is to protect it from oxidation while maintaining its performance equivalent to ITO. As discussed above, here are various substitutes available for ITO, but the successful candidate is MNWs networks or meshes which are capable of showing performance equivalent to ITO due to ease of synthesis via solution coating techniques. Moreover, MNWs networks or meshes are more flexible and stretchable as compared to ITO [5]. These nanowires based transparent conducting electrodes based devices or individual metal nanowires based nanodevices will be used under the harsh environment such as the upper space radiation environment.

Therefore, radiation effects study on these metal nanowires is important.

structure of nanomaterials in an excellent controllable way [6–10].

[20]. In addition, Co-NWs were irradiated with gallium (Ga<sup>+</sup>

**2. Effects of ion implantation on materials**

Damage to the structure of nanomaterials on contact to high energy ion beams has been the general perceptive, but recent research has made known it to be as a tool to tailor electronic, optical and field emission properties and to change the

Ion beam radiation effects on MNWs have been recently studied [11–16]. In literature, protons ions irradiated bismuth nanowires (Bi-NWs) were reported and found that electrical conductivity decreased with an increase in protons beam fluence due to crystal structural damage, while see-back coefficient remained unaffected. It was concluded that the crystal structure of Bi-NWs destroyed under protons irradiation, which consequently decreased mobility, whereas carrier concentration was unchanged [17]. Molecular dynamics simulations study was reported to examine a damage profile in Cu-NWs that occurred during exposure to ions beam having low energies [18]. A similar study has been done employing molecular dynamics simulations and found that mechanical properties of Cu-NWs are devastated due to ion beam irradiation [19]. Moreover, enhancement in conductivity of Cu-NWs is reported after their irradiation with gamma rays

the propagation field of domain walls is modified within the magnetic channels [21]. Moreover, interconnections through welding of various nanomaterials have also been built using different ion beams, which lead to enhance electrical con-

To understand ion implantation effects on nanomaterials clearly, one must be aware of radiations and basics of ion solid interaction mechanisms. However, the unfavorable outcomes of radiations are termed as radiation-induced damage. In the next section, the general effects of irradiation on materials are discussed briefly.

In ion beam implantation process principle is based on the extraction of beams of ions from the source and accelerate at a specific voltage often lies between 50 and 250 keV with a desired energy up to 10 MeV before transportation and impingement on the target or substrate [25]. The impingement causes the ions to interact with the specimen surface in which some are embedded in the specimen while some are scattered. Ion implantation is ingenious in surface modification of materials while retaining their bulk properties [25–27]. The beam implantation process, which can be static, broad and unidirectional, can either improve or cause a defect in the properties of materials like toughness, fatigue, wear, hardness, friction, dielectric, magnetic, electronic, resistive and superconductivity [25]. These effects are subjected to the applications of the prepared materials. This implantation can be done in materials like ceramics, insulators, semiconductors, metals, alloys and polymers. The magnitude of the defect caused in the materials depends majorly on

) Ions and found that

**4**

ductivity [22–24].

the mass of the incoming ion to the specimen, the accelerating voltage used for the beam, the thermal properties of the point defects confining the cascade region and the crystal structure of the specimen [25–28].

The most characteristic feature in ion implantation of materials is the generation of lattice disordered, which can be enhanced using low dose energy of heavy ions. In optical materials, ion implantation often stimulates luminescence to analyze the purity and point defects in the materials. Also, electro-optic, birefringence, refractive index, optical waveguide, reflectivity absorption band, thermoluminescence, electrical conductivity, piezoelectric, an optoelectric, and acoustic wave can be controlled with the effect of ion implantation [26–28].

The ion implantation effect also creates luminescence in some crystal materials. The luminesces observed during ion beam implantation in materials give information on the dynamic defect states owing to the transient features by the passage of ions that are difficult to excite. The defects observed can then be sensed by ion beam-induced luminescence and give information about the decay, impurities, or growth of the inherent defect state of the sample [24, 29].
