Highly Sensitive Acetone Gas Sensors Based on Erbium-Doped Bismuth Ferrite Nanoparticles

The acetone-sensing performance of BiFeO3 is related to structural phase transformation, morphology and band gap energy which can be modulated by rare-earth ions doping. In this work, Bi1−xErxFeO3 nanoparticles with different amounts of Er doping were synthesized via the sol-gel method. The mechanism of Er doping on acetone-sensing performance of Bi1−xErxFeO3 (x = 0, 0.05, 0.1 and 0.2) sensors was the focus of the research. The optimal working temperature of Bi0.9Er0.1FeO3 (300 °C) was decreased by 60 °C compared to BiFeO3 (360 °C). The Bi0.9Er0.1FeO3 sample demonstrated the optimal response to 100 ppm acetone (43.2), which was 4.8 times that of pure BFO at 300 °C. The primary reason, which enhances the acetone-sensing performance, could be the phase transformation induced by Er doping. The lattice distortions induced by phase transformation are favorable to increasing the carrier concentration and mobility, which will bring more changes to the hole-accumulation layer. Thus, the acetone-sensing performance of Bi0.9Er0.1FeO3 was improved.