Synthesis of indium tin oxide nanoparticles and application to near IR-reflective film

ITO nanoparticles were synthesized by coprecipitation method in an aqueous solution and thermal method in an alcohol solution. The coprecipitate prepared at room temperature showed the crystal structure of indium oxide in X-ray diffraction when it was annealed above 300 degreesC. In thermal method, the nanoparticles have two phase crystal structure of indium oxide hydroxide (InOOH) and indium hydroxide (In(OH)(3)). Annealing at the temperature above 300 degreesC, it showed the rhombohedral crystal structure of indium oxide (In2O3). The phase transition of ITO nanoparticle was also detected with DSC. Near IR-reflective film was prepared by spin coating using ITO sol solution. Transmission electron microsopy (TEM) and energy dispersive X-ray spectrometer (EDS) were used to characterize the morphology and composition of ITO nanoparticles. Near-IR (NIR) spectrometer was used to determine reflectance on the surface of ITO film in the NIR-radiation region.