All-inorganic lead-free Cs2XCl6 (X = Hf, Zr, Te) perovskites for humidity detection

• Published in: Applied surface science 2022-11, Vol.603, p.154423, Article 154423
• Main Authors: Chang, Qijie, Wu, Daofu, Huang, Yanyi, Liang, Chengyao, Liu, Libo, Liu, Huanbin, Liu, Yan, Qiu, Jing, Tang, Xiaosheng, Han, Genquan
• Format: Article
• Language: English
• Subjects: All-inorganic; Humidity sensor; Lead-free; Perovskite
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2022.154423

In this paper, all-inorganic lead-free Cs2XCl6 (X = Hf, Zr, Te) perovskites are synthesized via the solvothermal synthesis method and are employed to fabricate QCM humidity sensors. Fast response/recovery behaviors and considerable long-term stability are found, suggesting that the lead-free Cs2XCl6 (X = Hf, Zr, Te) perovskites could be favorable to humidity detection. [Display omitted] •Lead-free Cs2XCl6 (X = Hf, Zr, Te) perovskites were synthesized successfully.•Humidity sensors based on QCM and Cs2XCl6 (X = Hf, Zr, Te) perovskites were fabricated.•The as-prepared Cs2XCl6 (X = Hf, Zr, Te) humidity sensors demonstrated response/recovery behaviors (2.8 s/2.2 s, 3.8 s/2s and 3.7 s/2.1 s)•The proposed sensors exhibit excellent long-term stability (over 30 days) Lead halide perovskites are recently regarded as promising sensing materials owing to their sensitive surface characteristics and solution processability. However, the toxicity issue and intrinsic instability restrict their applications. Herein, lead-free Cs2XCl6 (X = Hf, Zr, Te) perovskites are employed to manufacture an environmentally friendly humidity sensor. With the assistance of quartz crystal microbalance (QCM), real-time and low-cost humidity sensors are performed. The as-prepared Cs2XCl6 (X = Hf, Zr, Te) humidity sensors exhibit ultrafast response/recovery behaviors (2.8 s/2.2 s, 3.8 s/2 s and 3.7 s/2.1 s) and considerable long-term stability (over 30 days). Furthermore, the bimodal exponential model is adopted to reveal the kinetics reactions of water molecules on the Cs2XCl6 (X = Hf, Zr, Te) coated QCM humidity sensors. All results suggest that the Cs2XCl6 (X = Hf, Zr, Te) coated QCM humidity sensors could be promising real-time humidity detection techniques.