Stable fluorescent NH3 sensor based on MAPbBr3 encapsulated by tetrabutylammonium cations

• Published in: Journal of alloys and compounds 2020-09, Vol.835, p.155386, Article 155386
• Main Authors: Li, Guishun, Zhang, Wenqian, She, Changkun, Jia, Shicheng, Liu, Shaohua, Yue, Fangyu, Jing, Chengbin, Cheng, Ya, Chu, Junhao
• Format: Article
• Language: English
• Subjects: Ammonia; Crystal structure; Detection; Differential thermal analysis; Differential thermogravimetric analysis; Fluorescence; Fourier transforms; Gas sensors; Germanium oxides; Infrared analysis; Infrared spectroscopy; Ligands; MAPbBr3; NH3 sensor; Optical properties; Perovskites; Photoluminescence; PL quenching; Recovery time; Response time; Selectivity; Sensors; Stabilizers (agents); Structure transformation; Substrates; Tetrabutylammonium ligand; Thermogravimetry
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.155386

Recently, organic-inorganic halide perovskite materials were investigated on gas sensing due to their excellent optical properties and gas sensitivities. Here, we designed a stable fluorescent perovskite-based sensor for NH3 detection, in which the CH3NH3PbBr3 (MAPbBr3) film was deposited on the GeO2 substrate and also capped by tetrabutylammonium (TBA) ligand as a stabilizing agent. This as-fabricated MAPbBr3-TBA-based sensor exhibited the relatively strong and stable photoluminescence (PL) intensity, thereby expanding the fluorescence response range for NH3 sensing. Upon exposure to NH3 gas, the PL intensity quenched rapidly by 62.5% with short response time (61 s) and recovery time (65 s). The sensor also possessed a linear relationship between the PL intensity and concentration of NH3 in the range of 0–100 ppm, and presented excellent reversibility, high gas selectivity, and humidity stability. Furthermore, the NH3 sensing mechanism was investigated based on X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Differential thermal analysis-Thermogravimetry (DTA-TG) and fluorescence lifetime measurements, in which the NH3 molecules might permeate the capped TBA ligand and then induce structure transformation of inner MAPbBr3 crystal. This study indicated that the as-prepared MAPbBr3-TBA-based sensor might provide promising applications on NH3 gas detection. •NH3 sensor was fabricated based on MAPbBr3 capped by tetrabutylammonium ligand (TBA).•The PL quenching reached to 62.5% with response time (61 s) and recovery time (65 s).•The sensor possesses excellent linearity, reversibility, selectivity and anti-humidity.•NH3 would permeate the capped TBA ligand, resulting in decomposition of perovskite.