Mala Siddaramappa - Siddaganga Institute of Technology, Tumakuru, India
Haraluru Kamala Eshwaraiah Latha - Siddaganga Institute of Technology, Tumkur
Haraluru Shankaraiah Lalithamba - Siddaganga Institute of Technology
Andi Udayakumar - Council of Scientific and Industrial Research-National Aerospace Laboratories

Indium tin oxide (ITO) nanoparticles were synthesized by green combustion method using indium (In) and tin (Sn) as precursors, and Carica papaya seed extract as novel fuel. This paper highlights effect of tin concentration (۵%, ۱۰% and ۵۰%) on microstructural, optical and electrical properties of ITO nanoparticles (NPs). The indium nitrate and tin nitrate solution along with the fuel were heated at ۶۰۰ °C for ۱ h in muffle furnace and obtained powder was calcinated at ۶۵۰ °C for ۳ h to produce ITO NPs. The above properties were investigated using XRD, FTIR, UV-Vis spectroscopy, SEM, TEM and computer controlled impedance analyser. The XRD, SEM and TEM investigations reveals the synthesized NPs were spherical in shape with an increase in average grain size (۱۷.۶۶ to ۳۵ nm) as Sn concentration increases. FTIR investigations confirms the In-O bonding. The optical properties results revealed that the ITO NPs band gap decreased from ۳.۲۱ to ۲.۹۸ eV with increase in Sn concentration. The ac conductivity of ITO NPs was found to increase with increase in Sn concentration. These synthesised ITO NPs showed the excellent properties for emerging sensor and optical device application.

Indium Tin Oxide, Green synthesis, Crystallite size, Band gap, Grain Boundary, AC conductivity