**4. ZnO doping**

Generally, the doping process is used for enhancing the electrical and the optical characteristics of the material [14]. The undoped *n*-type ZnO is usually due to the oxygen vacancies in the ZnO structure [15, 16]. This makes the doping process of ZnO as *p*-type is very difficult. There are several *p*-type dopants for ZnO nano materials. Lithium is one of the *p*-type dopants for the ZnO. It takes a centered position by replacing the zinc atoms in the wurtzite structure of the ZnO [17]. GaN can be used

**5**

**Figure 3.**

*ZnO nanowires [45].*

*Introductory Chapter: Overview of ZnO Based Nano Materials and Devices*

with ZnO to bypass the problem of *p*-type doping of ZnO nano material [18]. GaN is a wide band gap semiconductor with very similar lattice constants to ZnO. The GaN *p*-type dopant is commonly made with magnesium [18]. Several research groups have reported on the fabrication of ZnO hetero-junction devices. These heterojunctions devices used materials like silicon [19], aluminum gallium nitride [20], and gallium nitride [21] for the *p*-type semiconductors. The electrical resistivity is significantly decreasing for ZnO by using doping elements like aluminum [22], gal-

Recently, several efforts have been made for developing the ZnO film in different nanoshapes. These nanoshapes include the nanorods, nanowires, and nanocubes [23–26]. These nanoshapes of ZnO films can be used in several applications includ-

The nanoshapes of ZnO nanowires and nanorods based devices are becoming an important part of many potential applications. These applications include the optoelectronics, electromechanical nano devices [27] and biosensing [28].

There are several applications were reported based on ZnO based nanomaterials. These applications include the transparent electronic devices [29], the UV light emitters [30], the piezoelectric devices [31], the p-n junction devices [32], the field effect devices [33], the sensors [34], the optoelectronics [35], and the field emission

ZnO nanowires based devices have many research interests. Recently, many devices based on ZnO nanostructured nanowires were reported. This is due to the high surface area and the low cost of fabrication [37–40]. There are several fabrication methods being used for the growth of the ZnO nanowires. These methods include the vapor liquid solid [41], metal organic chemical vapor deposition [42], chemical bath deposition [43] and hydrothermal method [44] with varied film

lium [23], and indium [24]. The ZnO doping process is shown in **Figure 2**.

ing the UV laser emission, photodetector and LEDs devices.

qualities. The ZnO nanowires image is shown in **Figure 3**.

*DOI: http://dx.doi.org/10.5772/intechopen.85969*

**5. ZnO nanostructured material**

**6. ZnO nanowires based devices**

devices [36].

**Figure 2.** *ZnO doping process [25].*

*Introductory Chapter: Overview of ZnO Based Nano Materials and Devices DOI: http://dx.doi.org/10.5772/intechopen.85969*

with ZnO to bypass the problem of *p*-type doping of ZnO nano material [18]. GaN is a wide band gap semiconductor with very similar lattice constants to ZnO. The GaN *p*-type dopant is commonly made with magnesium [18]. Several research groups have reported on the fabrication of ZnO hetero-junction devices. These heterojunctions devices used materials like silicon [19], aluminum gallium nitride [20], and gallium nitride [21] for the *p*-type semiconductors. The electrical resistivity is significantly decreasing for ZnO by using doping elements like aluminum [22], gallium [23], and indium [24]. The ZnO doping process is shown in **Figure 2**.

### **5. ZnO nanostructured material**

*Zinc Oxide Based Nano Materials and Devices*

shown in **Figure 1**.

*ZnO different crystalline structures [3].*

**Figure 1.**

**4. ZnO doping**

of ZnO lead to a perfect polar symmetry along the hexagonal axis of the ZnO's crystalline structure. The ZnO based piezoelectricity and spontaneous polarization are due to these crystalline structures. The two ZnO's crystalline structures are

Generally, the doping process is used for enhancing the electrical and the optical characteristics of the material [14]. The undoped *n*-type ZnO is usually due to the oxygen vacancies in the ZnO structure [15, 16]. This makes the doping process of ZnO as *p*-type is very difficult. There are several *p*-type dopants for ZnO nano materials. Lithium is one of the *p*-type dopants for the ZnO. It takes a centered position by replacing the zinc atoms in the wurtzite structure of the ZnO [17]. GaN can be used

**4**

**Figure 2.**

*ZnO doping process [25].*

Recently, several efforts have been made for developing the ZnO film in different nanoshapes. These nanoshapes include the nanorods, nanowires, and nanocubes [23–26]. These nanoshapes of ZnO films can be used in several applications including the UV laser emission, photodetector and LEDs devices.

The nanoshapes of ZnO nanowires and nanorods based devices are becoming an important part of many potential applications. These applications include the optoelectronics, electromechanical nano devices [27] and biosensing [28].

There are several applications were reported based on ZnO based nanomaterials. These applications include the transparent electronic devices [29], the UV light emitters [30], the piezoelectric devices [31], the p-n junction devices [32], the field effect devices [33], the sensors [34], the optoelectronics [35], and the field emission devices [36].

### **6. ZnO nanowires based devices**

ZnO nanowires based devices have many research interests. Recently, many devices based on ZnO nanostructured nanowires were reported. This is due to the high surface area and the low cost of fabrication [37–40]. There are several fabrication methods being used for the growth of the ZnO nanowires. These methods include the vapor liquid solid [41], metal organic chemical vapor deposition [42], chemical bath deposition [43] and hydrothermal method [44] with varied film qualities. The ZnO nanowires image is shown in **Figure 3**.

**Figure 3.** *ZnO nanowires [45].*
