Influence of hydrothermal temperature on structures and photovoltaic properties of SnO_2 nanoparticles

摘要

Two SnO_2 nanoparticles were synthesized by hydrothermal method at 170 ℃ and 180 ℃, respectively, Transmission electron microscope observations reveal that the diameters of both the nanoparticles are around 6 nm. At the same time, surface photovoltage spectroscopy measurements show that the nanoparticle synthesized at 180 ℃ has more surface electronic states at 0.3 eV below the conduction band than the one synthesized at 170 ℃. This means that the temperatures chosen in hydrothermal synthesis have significant influence on the surface electronic characteristics of resultant SnO_2 nanoparticles but the effect on their sizes is not obvious. However, after being calcined at 500 ℃ for 2 h, the diameter of the nanoparticle synthesized at 180 ℃ increased to 23 nm and that of the nanoparticle synthesized at 170 ℃ increased to 32 nm as calculated from X-ray diffraction pattern.