**1. Introduction**

Metal oxide thin film plays an important role in various applications such as aircraft cockpits, electronic displays, medical devices, solar panels, smart windows and high-temperature sensors in spacecraft, photonics, photodetectors, infrared detectors, phototransistors, transparent electronics, optics, anti-reflective and decorative coatings [1]. They own excellent banding and carrier mobility for conduction phenomena in the field effect transistor application. The semiconductor industry flourished from a simple Si-based metal oxide semiconductor field effect transistor to an era of MOSFET-based smart materials. In recent decades, researchers have been replacing all the materials needed for the MOSFET unit. They replaced the substrate with flexible materials, light weight material, transparent

material, etc. They also come up with the idea of replacing dielectric silicon dioxide material with high-grade dielectric materials. And changing the channel in the MOSFET has become the latest trend in FET research. From the bulk to the atomic level, transistors have been interestingly studied around the globe for the application of electronic devices. This research was therefore motivated by the various semiconductor materials applicable to the replacement of the dielectric channel/ gate [2, 3].

Research focuses on various materials such as zinc oxides (ZnO), electrochromic oxides such as molybdenum oxides (including MoO3 and MoO2) and various binary oxides using ZnO and MoO3. New electrical results are studied with the investigation of the conduction mechanism using ac complex impedance spectroscopy with ZnO and MoO3 binary oxides. This has motivated the research to work on new binary materials with ZnO /TiO2 and ZnO /V2O5. As a result, we investigated the various electrical properties and complex impedance parameters using ac impedance spectroscopy. An attempt with pulsed laser deposited ZnO thin film as a channel layer and Al2O3 as a dielectric layer in FET was fabricated and studied. A transistor with ZnO channel, MoO3 as an interlayer with source-substrate and drain-substrate, and a layer of binary oxides ZnO/MoO3 and ZrO2 as a dielectric stack layer is also manufactured and analysed.

The primary objective of this research is to study the pulsed laser deposited thin films such as ZnO, MoO3, binary oxides such as ZnO/MoO3, ZnO/TiO2 and ZnO/ V2O5 and their behaviour as gate dielectric layer to investigate the IV properties for FET applications. To achieve the objective following work elements were set: First to investigate the pulsed laser deposited thin films of ZnO nanostructures with the effects of laser repetition rate and deposition temperatures, then an investigation of the MoO3 and MoO2 thin films by pulsed laser deposition with the impact of O2 and Ar atmosphere gas and deposition temperatures. The research continued its next set of investigation of the current conduction mechanism of the pulsed laser deposited binary oxide ZnO/MoO3, ZnO/TiO2 and ZnO/V2O5 thin films using ac complex impedance spectroscopy and the impact of wide range of temperature from 298 K to 423 K and a wide range of frequency from 1 Hz to 1 MHz. Finally, a ZnO thin film by pulsed laser deposition as n-channel MOSFET and its performance of ZnO channel along with various binary oxides and interlayer MoO3 in MOSFET were studied [4].

## **2. Materials and methods**

#### **2.1 General information on zinc oxide**

Zinc oxide is a unique material that exhibits exceptional semiconducting, piezoelectric, and pyroelectric properties. Nanostructures of ZnO are equally as important as carbon nanotubes and silicon nanowires for nanotechnology and have great potential applications in nanoelectronics, optoelectronics, sensors, field emission, light-emitting diodes, photocatalysis, nanogenerators, and nanopiezoelectronics. Fundamental understanding about the growth of ZnO nanowires is of critical importance for controlling their size, composition, structure, and corresponding physical and chemical properties [5].

#### **2.2 General information on transition metal oxide**

Moreover, the MoO3, V2O5 and TiO2 belong to the transition metal oxides (TMO) family. Hence these mixed metal oxides MoO3, V2O5 and TiO2 also called as binary

**47**

**Table 1.**

*Binary Metal Oxides Thin Films Prepared from Pulsed Laser Deposition*

transition metal oxides (BTMOs). They consist of at least one transition metal ion and one or more electrochemically active/inactive ions. They can use the synergism behavior of pure oxides, which can enrich the capacitive performance with an expanded potential window, supplementary active sites, excellent conductivity and improved stability. According to Zhang et al. [6], BTMOs possess higher reversible capacity, better structural stability and electronic conductivity, and have been

widely studied to be novel electrode materials for transistor applications.

**Table 1** provides the basic properties of ZnO, MoO3, TiO2 and V2O5.

The various thin film deposition methods are sol–gel deposition, thermal electrodeposition, chemical vapor deposition, sputtering, atomic layer deposition, pulsed laser deposition and so on. Among these the pulsed laser deposition is a sophisticated, rich and excellent deposition method especially for metal oxides

A pulsed laser beam is allowed to hit the target material which is placed on the target holder. This is fixed with the rotating target carrousel. A laser plume consisting of atoms, molecules, ions, nanoparticles and microparticles also known as plasma produced. This plasma of molten material by the pulsed laser starts

Molecular formula ZnO MoO3 TiO2 V2O5 Molar mass (g/mol) 81.39 143.94 79.87 149.88

Odor Odorless Odorless Odorless Odorless

Refractive index 2.0041 2.5166 2.9103 2.3 Melting point 2248 K (decomposes) 1068 K 2128 K 2213 K Boiling point 2633 K 1428 K (sublimes) 3273 K 2023 K

Dielectric constant 8.33 35 80 37.2

) 5.61 4.70 4.23 3.36

**oxide**

to slightly bluish powder or granules

0.49 g/1000 mL in water at 28 °C

**Titanium dioxide**

> White powder

Insoluble in water

(indirect)

67-7

**Vanadium pentoxide**

Yellow to red crystalline powder

(decomposes)

1 g / 125 mL (slightly soluble)

2.8 (indirect)

1314-62-1

**Properties Zinc oxide Molybdenum** 

Appearance White solid Colorless or white

(at 30 °C) (Insoluble in water)

Bandgap (eV) 3.34 (direct) 2.9 (direct) 3.2

CAS number 1314-13-2 1313-27-5 13463–

*DOI: http://dx.doi.org/10.5772/intechopen.96161*

**2.3 Basic properties of ZnO, MoO3, TiO2 and V2O5**

**2.4 Pulsed laser deposition**

(MO) thin films depositions.

**2.5 Physical principle**

Density (g/cm3

Solubility in water 0.16 mg/100 mL

*Basic properties of the ZnO, MoO3, TiO2 and V2O5.*

*Binary Metal Oxides Thin Films Prepared from Pulsed Laser Deposition DOI: http://dx.doi.org/10.5772/intechopen.96161*

transition metal oxides (BTMOs). They consist of at least one transition metal ion and one or more electrochemically active/inactive ions. They can use the synergism behavior of pure oxides, which can enrich the capacitive performance with an expanded potential window, supplementary active sites, excellent conductivity and improved stability. According to Zhang et al. [6], BTMOs possess higher reversible capacity, better structural stability and electronic conductivity, and have been widely studied to be novel electrode materials for transistor applications.
