Noticeable enhancement in NH3 sensing performance of nebulizer spray pyrolysis deposited SnO2 thin films: An effect of Tb doping

Rare metal Terbium (Tb) doped SnO2 (SnO2:Tb) films were fabricated via spray pyrolyzed method with different doping concentrations. The effects of terbium doping concentration on its microstructural, optical, photoluminescence, and room temperature ammonia vapor sensing properties were reported. The crystallite size of the prepared Tb-doped tin oxide films decreases with an increase in doping concentrations. The obtained crystallite size ranges from similar to 12 - 9 nm. The terbium incorporation was confirmed by EDS and elemental mapping. The bandgap values are enhanced as the concentration of Tb doping increases. The high gas response of 79% with fast response/recovery of 31/11 s, respectively is reported for 25 ppm of ammonia at room temperature for 5% Tb doped sample. The gas sensing cycle test shows the excellent sensitive behavior of the films without any decrease upon 5 repeated cycles. The stability of the sample was also checked for a corresponding Tb 5% doped sample, which revealed a stable response even for 50 days.

Automated summary

The research investigated the effects of terbium doping concentration on the microstructural, optical properties, and ammonia gas sensing characteristics of tin oxide films. Results showed that the crystallite size decreased and bandgap values increased with higher terbium doping concentrations. A high gas response and fast response/recovery were reported for the 5% terbium doped sample.