Section 4 ZnO Applications

*Zinc Oxide Based Nano Materials and Devices*

[16] Tyona MD, Osuji RU, Ezema FI. A review of zinc oxide photoanode films for dye-sensitized solar cells based on zinc oxide nanostructures. Advanced

[24] Shannon RD. Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallogr. Sect. A.

[25] Mkawi EM, Ibrahim K, Ali MKM, Farrukh MA, Mohamed AS. The effect of dopant concentration on properties of transparent conducting Al-doped ZnO thin films for efficient Cu2ZnSnS4 thin-film solar cells prepared by electrodeposition method. Applied

[26] Mani GK, Rayappan JBB. Influence

[27] Sun RD, Nakajima A, Fujushima A,

[28] Sun H, Luo M, Weng W, Cheng K, Du P, Shen G, et al. Room-temperature preparation of ZnO M nanosheets grown on Si substrates by a seed-layer assisted solution route. Nanotechnology.

of copper doping on structural, optical and sensing properties of spray deposited zinc oxide thin films. Journal of Alloys and Compounds.

Nanoscience. 2015;**3**:56-67

Watanabe T, Hashimoto K. Photoinduced surface wettability conversion of ZnO and TiO2 thin films. The Journal of Physical Chemistry. B.

2014;**582**:414-419

2001;**105**:1984-1991

2008;**19**:125603-125610

1976;**32**:751-767

[17] Shinde NM, Dubal DP, Dhawale DS, Lokhande CD, Kim JH, Moon JH. Room temperature novel chemical synthesis of Cu2ZnSnS4 (CZTS) absorbing layer for photovoltaic application. Materials Research Bulletin. 2012;**47**:302-307

[18] Machado G, Guerra DN, Leinen D, Ramos-Barrado JR, Marotti RE, Dalchiele EA. Indium doped zinc oxide thin films obtained by electrodeposition. Thin Solid Films.

Lokhande CD, Banpurkar AG, Osuji RU, Ezema FI. Dye-sensitized solar cells based on Al-doped ZnO photoelectrodes sensitized with rhodamine. Materials

[21] Muthukumaran S, Gopalakrishnan R. Structural, FTIR and photoluminescence studies of Cu doped ZnO nanopowders by coprecipitation method. Optical Materials. 2012;**34**:1946-1953

[22] Babikier M, Wang D, Wang J, Li Q, Sun J, Yan Y, et al. Cu-doped ZnO nanorod arrays: The effects of copper precursor and concentration. Nanoscale

Research Letters. 2014;**9**:199-207

[23] Thakur S, Sharma N, Varkia A, Kumar J. Structural and optical properties of copper doped ZnO nanoparticles and thin films.

Advances in Applied Science Research.

Nano Research. 2013;**1**:43-58

2005;**490**:124-131

2014;**60**:27-31

[19] Tyona MD, Jambure SB,

Letters. 2018;**220**:281-284

[20] Becerril M, Silva-López H, Guillén-Cervantes A, Zelaya-Ángel O. Aluminum-doped ZnO polycrystalline films prepared by co-sputtering of a ZnO-Al target. Revista Mexicana de Física.

**74**

2014;**5**:18-24

Chapter 5

Abstract

Application

increase in carbon dopant level.

1. Introduction

77

Pyrolysis of Carbon-Doped ZnO

It is very important to find new methods for improving the properties of nanostructured materials that can be used to replace the highly expensive and complicated techniques of fabricating ZnO nano-powders for solar cell applications. Pneumatic spray pyrolysis method offers a relatively inexpensive way of fabricating ZnO nanomaterials of controllable morphology, good crystallinity and uniform size

nanoparticles. Additionally, it has the advantage of producing ZnO NPs in one step directly on the substrate without the need for other wet chemistry processes like purification, drying and calcination. To that end, the present study emphasizes more on the design and optimization of spray pyrolysis system as well as on the pneumatic spray pyrolysis conditions for the production of carbon-doped ZnO nanoparticles. The un-doped and carbon-doped ZnO NPs were prepared using pneumatic spray pyrolysis employing zinc acetate as a precursor solution and tetrabutylammonium as a dopant. The fabricated un-doped and C-ZnO NPs were characterized for their morphological, structural and optical properties using SEMEDX, XRD and DRS. SEM analysis has revealed that the fabricated un-doped and C-ZnO NPs have spherical shape with mesoporous morphology. The crosssectional SEM has also revealed that the film thickness changes with increasing dopant concentration from 0.31 to 0.41 μm at higher concentrations. Moreover, the

distribution, which makes it a good candidate for the production of ZnO

EDX spectra have confirmed the presence of Zn and O atoms in the PSP-

synthesized ZnO NPs. XRD analysis of both un-doped and C-ZnO has revealed the peaks belonging to hexagonal Wurtzite structure of ZnO. Additionally, the DRS has revealed a decrease in energy band gap of the synthesized ZnO NPs, with the

Keywords: spray pyrolysis, zinc oxide, nanoparticle, pneumatic spray pyrolysis

In recent decades, semiconducting metal oxide materials such as zinc oxide (ZnO), tin oxide (SnO2), iron oxide (Fe2O3) and titanium dioxide (TiO2) have become an area of research due to their great potential to solve environmental problems [1]. These wide-band-gap semiconductors are considered to have the ability to easily adjust the optoelectronic and transport properties of the metal oxide semiconductor material which makes them the promising candidates for several

Nanoparticles for Solar Cell

Luyolo Ntozakhe and Raymond Tichaona Taziwa
