Optical Conductivity Analysis of Green CuO Nanoparticles Using Plant Leaf Extract

The optical properties of green synthesized CuO nanoparticles such as absorption coefficient, refractive index, band gap, dielectric constant and optical conductivity were analyzed. XRD shows that upon temperature treatment of green CuO nanoparticles, the crystal size increases and thus the crystallinity increases due to the decrease in the number of crystals per unit area. Due to the high crystallinity, the absorption coefficient exhibits a high electronic shift and the refractive index exhibits good polarization of the ions. Thus the dielectric constant of the real and imaginary regions decreases as the photon energy increases. Higher temperatures exhibit higher photon energy levels. Optical conductivity has induced electron annihilation due to the absorption coefficient of increased photo energy light; Hence the optical conductivity analysis of Lantana camara capped CuO nanoparticles indicated the stability of electrical conductivity with increase in photo power.


INTRODUCTION
Recent years have seen new trends in research speed, low cost and high energy.In this view, energies are measured quantum mechanically and the quantum field is often associated with thermodynamics and optics.The main role of optics is leading in electromagnetics, because light has dual properties like wave and particle, and it transfers information from one place to another faster, with less energy loss, less cost and more energy conversions.Optical conductivity can be measured depending on the light absorption and refractive index of the surface volume ratio of materials, because these two phenomena are related to the workability of the material, which is determined by its surface to volume ratio.The surface-to-volume ratio shows many ways to create new materials [1,2].
It plays an important role in the field of all materials and facilitates the chemical process.The surface area to volume ratio of nanoparticles has a significant effect on nanoparticle properties.Nanoparticles have a relatively large surface area compared to the same volume of matter.The radius of the sphere decreases the surface area.Here we can also conclude that when a given volume is divided into IOP Publishing doi:10.1088/1757-899X/1291/1/012025 2 smaller pieces, the area increases.Thus as the particle size decreases, a larger fraction of atoms is found on the surface than inside [3,4].Because the growth and catalytic chemical reactions occur at the surface, the nanomaterial is more reactive than the same mass composed of larger particles.It has also been found that materials that are stable in their bulk form react when produced in their nanoscale form [5,6].This can improve their properties.So in this formulation, we analyze absorption coefficient, refractive index, band gap and optical conductivity of green synthesized CuO nanoparticles for electrical conductivity.

SYNTHESIS OF COPPER OXIDE NANOPARTICLES Figure 1 Schematic Diagram of Synthesis of CuO Nanoparticles
The Cleaned Lantana camara leaves chop it into small pieces and take 5g of chopped Lantana camara leaves in 250ml glass beaker and add 100ml of deionised water to it.Then it should be placed on the magnetic stirrer and stirred for 20 minutes at a temperature of 80 degrees.After 20 minutes, the extract of lantana camara leaves keep it.
Copper oxide nanoparticles were prepared by sol-gel method using Lantana camara leaf     The FTIR spectrum of green synthesized CuO nanoparticles shown in figure 3.This FTIR spectrum revealed that peaks at 424, 522 and 601cm -1 has formation of CuO nanoparticles [9].The broad peak at 3029Cm -1 is attributed to O-H stretching of moisture content [10].The Peak obtained at 2354cm -1 has stretching vibration of O=C=O bond of carbon dioxide [11].The peak observed at 1389cm -1 is bending vibration of phenol [12].

Absorption Coefficient
Absorption coefficient of green synthesizes CuO nanoparticles by UV Visible spectra as shows in the figure 4. In figure 4 shows that that lowers temperatures has high absorption and higher temperature has low absorption.But all the three temperatures of samples has higher absorption 1291 (2023) 012025 IOP Publishing doi:10.1088/1757-899X/1291/1/0120255 coefficient and its indicated density of electron absorb by medium of material.The absorbed by the materials is converted into heat of the material due to which electron is excited by photon energy and electron-hole fusion is formed [13].So green synthesized CuO nanoparticles of 400oC and 500 o C temperatures of higher edge absorption exhibited 1.7ev of photon energy and 450 o C temperature of higher edge absorption exhibited 1.5eV.The absorption of light is reduces in higher photon energies.
The Absorption coefficient is calculated by [14] Absorption Coefficient  = . ----------------- [11,15].Since the wavelength of the ultraviolet region is easily scattered, the electron is excited by the photon.This type of UV absorption is associated with electronic transition in molecules from lower energy to higher energy states.The position of the atoms in a molecule that includes the orbital's involved in the transition is said to produce a transition of electron-hole combinations.

Morphological Studies
Scanning electron microscopy (SEM) images of CuO metallic nanoparticles synthesized by Sol-gel method respectively.SEM has been used to recognize the size, shape and morphology of nanoparticles.It reveals that the CuO nanoparticles are well dispersed and for the most part of spherical in shape.CuO have a standardized particle shape and size with little bit of agglomeration because they did not form a large cluster.The agglomeration can generally be confirmed by the formation of large cluster [15,16].assortment between 18 to 21nm.This deviation in particle size strengthens with XRD analysis.Figure 5 shows the three dimensional aggregate morphology of as synthesized material, which formed by a group of primary particles [17].----------------- The absorbed light has damp in the small area and interacted with electron in nanoparticles for induced electric conductivity [21].From the figure 5 the extinction coefficient in photon energy is increase then decrease in higher energy value and it has constant move but it comes not zero and also in wavelength has increases temperature with increase the extinction coefficient in higher wavelength.So extinction coefficient analysis of green synthesized CuO nanoparticles clearly reveals that suitable material for optical conductivity.

Optical Conductivity
Optical conductivity is a property of a material that gives a relationship between the induced current density in the material and the magnitude of induced electric field for arbitrary frequencies [24].In this article analysed to optical conductivity of Green synthesized CuO nanoparticles by using Lantana camara leaf extract.The Optical conductivity of Green synthesized CuO nanoparticles as shown in figure 9.The Figure 9 exhibits high intensity of optical conductivity appeared at 1.7eV in photon energy and 680nm, 804nm in wavelength.and increasing the photon energy.This increased photo energy has induced electron extinction due to absorption coefficient of light [25,26].So that the optical conductivity analysis of Lantana camara capped CuO nanoparticles of figure 9 reveals that the assurance of the electrical conductivity on the increases in photo energy.Finally, concluded form the figure 9 of optical conductivity, the obtained green synthesized CuO nanoparticles has opted to optical devices.The table 2 reveals that the optical perameters such as optical band gap (Eg), Urbach energy (Eu) and optical conductivity.

Dielectric Constant
The dielectric constant of Green synthesized Nanoparticles as shown in figure 10.The real part of dielectric larger negative values for 500 O C than for 400 O C and 450 O C and imaginary part of dielectric constant exhibits inter band transition in ultra violet part of spectra.The real part of Dielectric constant is the factor that slows down the speed of light and thus leads to the ability of materials to electrical conductivity.Likewise, the imaginary dielectric constant acts as a measure of the material's light absorption and hence the ability to conduct electricity through dipole mobility [27].The figure 8 shows dielectric constant of real and imaginary parts decreases with increases in photon energy.It's indicated the higher temperatures exhibit the higher photon energy level.

Figure 2 .
Figure 2. XRD Analysis of CuO Nanoparticles at Different Temperatures density and Micro strain.At each temperature there is change in the surface to volume ratio due to the change in micro strain and dislocation density.The surface to volume ratio change is plotted on the stacking fault in table 1.The analysis of XRD figure1 shows that the rise of the temperature treatment of green CuO nanoparticles has leads increases crystallinity with increases crystal size and decreases magnitude of number of crystallites per unit surface area.

Figure 3 .
Figure 3. FTIR Spectra of Bio-synthesized CuO NPs at Different Temperatures

1 Figure 4 .
Figure 4. Absorption Coefficient of Green synthesized CuO NPs at Different Temperatures

6 Figure 5 .
Figure 5. Morphological Analysis of Bio-synthesized CuO NPs at different Temperature .SEM Micrograph represents a position of Copper Oxide nanoparticles, which may be reaction in high temperatures.The crystal grain size calculated from SEM micrograph originated to

Figure 6
represents the refractive index of the green synthesized CuO nanoparticles at three different temperatures.The refractive index of the photon energy plot of green synthesized CuO nanoparticles shows in figure 6.The image clearly revealed that refractive index increases with increases in photon energy.The refractive index increases with increases optical density and speed of light decreases.The optical density of a material is related to the inertial tendency of the atoms of a material to retain the absorbed energy of an electromagnetic wave in the form of vibrating electrons before giving it back as a new electromagnetic disturbance.The more optically dense a material is, slower a wave travels through the material [18].Refractive Index  =    +    −

Figure 8 .
Figure 8. Band gap of Green synthesized CuO NPs at Different Temperatures

Figure 9 .
Figure 9. Optical Conductivity of Green synthesized CuO NPs at Different Temperatures

Figure 10 .
Figure 10.Dielectric Constant of Green synthesized CuO NPs at Different Temperatures colour and a black precipitate can be observed in the bottom of beaker.The precipitate was taken and washed twice with deionised water and the filtered.The obtained black powder was subjected to three different sintering (400 O C, 450 O C and 500 O C) to prepare CuO nanoparticles.The prepared CuO nanoparticles samples were subjected to characterization. Figure 1 Schematic Diagram of Synthesis of

Table 1 .
Structural Parameter of Green Synthesized CuO Nanoparticles The green synthesized CuO nanopaticles at different temperature treatment reveals similar structural results observed XRD analysis.The green capped CuO nanoparticles main peaks positioned at 35.7 O and 38.2 O is consistent with JCPDS 45-0937 [8].Lantana Camara leaf capped CuO nanoparticles has modified by plant extract ions to increase the crystal size when increase temperatures.Table 1 exhibits the structural parameters like crystal size, Micro strain, stacking fault and dislocation density.The Table 1 crystal size increases with decreases stacking fault, dislocation 4