The Effect of Tin Concentration on Microstructural, Optical and Electrical Properties of ITO Nanoparticles Synthesized Using Green Method

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 the effect of tin concentration (5%, 10%, and 50%) on the microstructural, optical, and electrical properties of ITO nanoparticles (NPs). The indium nitrate and tin nitrate solution along with the fuel were heated at 600°C for 1 h in a muffle furnace and obtained powder was calcinated at 650°C for 3 h to produce ITO NPs. The above properties were investigated using XRD, FTIR, UV-Vis spectroscopy, SEM, TEM, and computer-controlled impedance analyzer. The XRD, SEM, and TEM investigations reveal the synthesized NPs were spherical in shape with an increase in average grain size (17.66 to 35 nm) as Sn concentration increases. FTIR investigations confirm the In-O bonding. The optical properties results revealed that the ITO NPs band gap decreased from 3.21 to 2.98 eV with an increase in Sn concentration. The ac conductivity of ITO NPs was found to increase with an increase in Sn concentration. These synthesized ITO NPs showed excellent properties for emerging sensor and optical device applications.