Synthesis, Characterization, and Humidity Detection Properties of Nb2O5 Nanorods and SnO2/Nb2O5 Heterostructures

Nanostructurecl metal oxide semiconductors are ideally suited for their integration in different devices due to their high thermal and mechanical stability, unique electronic characteristics, and low-cost fabrication. The modification of their surface allows the design of heterostructures with novel properties. In this work, we have synthesized single-crystalline niobium pentoxide (Nb2O5) nanorods and niobium-pentoxide-coated tin oxide (Nb2O5/SnO2) heterostructures by chemical vapor deposition. HR-TEM analysis and computer simulation studies showed the low density of defects and high crystallinity of the Nb2O5 nanorods, which exhibited high sensitivity toward humidity at low temperatures (60 degrees C). The fabrication of SnO2/Nb2O5 core-shell heterostructures combines the high sensitivity of Nb2O5 shell toward moisture with the good electrical conductivity of SnO2. The growth of the nanoscopic Nb2O5 overlayer on SnO2 nanowires introduces defects in the structure, which influence the electronic properties of the material and enable the design of more efficient humidity sensors.