Shi Xiaobo, Jiang Shujuan, Han Xianwei, Wei Min, Wang Bing, Zhao Gaofeng, Zheng Guang-Ping, Yin Huabing
Institute for Computational Materials Science, International Joint Research Laboratory of New Energy Materials and Devices of Henan Province, School of Physics and Electronics, Henan University, Kaifeng 475004, China.
Institute of Artificial Intelligence, Henan Finance University, Zhengzhou 450046, China.
Phys Chem Chem Phys. 2022 Apr 6;24(14):8371-8377. doi: 10.1039/d2cp00918h.
InSeBr-Type monolayers, ternary In(Se,S)(Br,Cl) compounds, are typical two-dimensional (2D) Janus materials and can be exfoliated from their bulk crystals. The structural stability, electronic properties, mechanical flexibility, and intrinsic piezoelectricity of these InSeBr-type 2D Janus monolayers are comprehensively investigated by first-principles calculations. Our calculations show that the stable InSeBr-type monolayers exhibit ultrahigh mechanical flexibility with low Young's moduli. Due to the amazing flexibility of the InSeBr monolayer with an ultra-low Young's modulus of 0.81 N m, the piezoelectric strain coefficient can reach 10 pm V orders of magnitude (around 2361-3224 pm V), which is larger than those of reported 2D materials and even superior to those of conventional perovskite bulk materials. Such a superior piezoelectric response of InSeBr-type monolayers could facilitate their practical applications in sensors and energy harvesters.
InSeBr型单层材料，即三元In(Se,S)(Br,Cl)化合物，是典型的二维（2D）Janus材料，可从其块状晶体中剥离出来。通过第一性原理计算，对这些InSeBr型二维Janus单层材料的结构稳定性、电子性质、机械柔韧性和固有压电性进行了全面研究。我们的计算表明，稳定的InSeBr型单层材料表现出超高的机械柔韧性和低杨氏模量。由于InSeBr单层材料具有超低的杨氏模量（0.81 N/m），其压电应变系数可达到10 pm/V数量级（约为2361 - 3224 pm/V），这比已报道的二维材料还要大，甚至优于传统的钙钛矿块状材料。InSeBr型单层材料如此优异的压电响应有助于它们在传感器和能量收集器中的实际应用。
