Mechanics, Materials Science & Engineering, May 2017
ISSN 2412-5954
Variation in Structural and Optical Properties of Al Doped ZnO Nanoparticles Synthesized by Sol-gel Process7 Vanaja Aravapalli1, Seshu Kalakatla1, G. K. S. Prakash Raaju2, Srinivasa Karumuri3 1
Asst. Professor, Dept. of AS&H, Tirumala Engineering College, Jonnalagadda, India
2
Research fellow, CMET (Govt. of India), Hyderbad, India
3
Professor, Dept of ECE, KL University, Vaddeswaram, India DOI 10.2412/mmse.23.89.710 provided by Seo4U.link
Keywords: aluminum nanoparticles, ZnO, XRD, SEM, UV-Vis, PL.
ABSTRACT. This article focuses on analyzing structural and optical properties of Al doped ZnO (AZO) synthesized with two different precursors aluminum chloride and aluminum nitrate. The nanoparticles were successfully fabricated and characterized at room temperature by sol-gel process. The objective of improving properties of ZnO nanoparticles by introducing dopants was successful with formation of nanoparticles having different crystalline sizes, optical absorption and luminescence properties. The two different sources influenced properties of ZnO. The particles with less crystalline size obtained from aluminum nitrate. Change in morphology from spherical to bar like morphology proved from SEM spectra. Presence of functional groups predicted from FTIR spectra. PL spectra proved UV emission and visible emission for AZO nanoparticles synthesized using dopant sources aluminum chloride and aluminum nitrate respectively. The obtained properties prove successful utilization of AZO nanoparticles as building materials in fabrication of optoelectronic devices.
Introduction: Recent days ZnO nanoparticles widely utilized in fabrication of various optoelectronic ics of large and direct band gap, high melting point, thermal conductivity, mobility, inexpensive, luminescence etc. Introducing dopants in ZnO lattice helps in tuning the properties of ZnO nanoparticles [1]. Transition metal ions can be easily penetrated into ZnO lattice because they have ionic radius which is very close to ZnO. In present work, AZO nanoparticles are synthesized by choosing different dopant sources aluminum chloride and aluminum nitrate. AZO is also a promising material for high temperature thermo electronic material. ZnO nanoparticles obtained by replacing Zn2+ with high valence electrons like Al, Ga, In etc regarded as promising materials for optoelectronic device fabrication [2]. AZO nanoparticles is also highly promising as a potential high-temperature thermoelectric material. Al ion can be easily incorporated into ZnO lattice due to its ionic radius near to that of ZnO [3]. AZO nanopowders can be utilized as transparent conductive pastes because of their properties of transparency and conductivity in visible region. ZnAlO is a wide band gap material (Eg~3.8eV). Top down and bottom up approaches were reported in literature for synthesizing nanoparticles. Bottom up methods were more preferred because of their less wastage, high purity etc. [4]. With the development in field of nanoresearch various bottom up techniques like co precipitation, hydrothermal method, laser ablation etc were developed for nanoparticle synthesis [5]. In this work sol-gel method is used for synthesis of AZO nanoparticles. This method is simple, inexpensive, environment friendly. By this method it is possible to control particle size, morphology, high degree of crystallinity, higher nucletion rates etc. The sol-gel process is carried out at room temperature [6]. In this work, AZO nanoparticles were prepared by sol-gel process employing ZnCl2, NaOH, Aluminium nitrate, Aluminium chloride and ethanol as starting materials. The particles were 7
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