2018, Dou, Shaoxu, Qi, Mengke, Chen, Cong, Zhou, Hong, Wang, Yong, Shang, Zhengguo, Yang, Jing, Wang, Dengpan, Mu, Xiaojing

A piezoelectric AlN-on-SOI structured MEMS Lamb wave resonator (LWR) is presented for high-temperature strain measurement. The LWR has a composite membrane of a 1 μm thick AlN film and a 30 μm thick device silicon layer. The excited acoustic waves include Rayleigh wave and Lamb waves. A tensile strain sensor has been prepared with one LWR mounted on a uniaxial tensile plate, and its temperature characteristics from 15.4°C to 250°C and tensile strain behaviors from 0 μϵ to 400 μϵ of Rayleigh wave and S4 mode Lamb wave were tested. The temperature test verifies the adaptability of the tensile strain sensor to temperature up to 250°C, and S4 mode Lamb wave and Rayleigh wave represent almost the same temperature characteristics. The strain test demonstrates that S4 mode Lamb wave shows much higher strain sensitivity (-0.48 ppm/μϵ) than Rayleigh wave (0.05 ppm/μϵ) and confirms its advantage of strain sensitivity. Finally, for this one-LWR strain sensor, a method of beat frequency between S4 mode Lamb wave and Rayleigh wave is proposed for temperature compensation and high-sensitivity strain readout.

2023, Feng, Shien-Ping, Cheng, Yuanhang, Yip, Hin-Lap, Zhong, Yufei, Fong, Patrick W. K., Li, Gang, Ng, Annie, Chen, Cong, Castriotta, Luigi Angelo, Matteocci, Fabio, Vesce, Luigi, Saranin, Danila, Carlo, Aldo Di, Wang, Puqun, Wei Ho, Jian, Hou, Yi, Lin, Fen, Aberle, Armin G, Song, Zhaoning, Yan, Yanfa, Chen, Xu, Yang, Yang (Michael), Syed, Ali Asgher, Ahmad, Ishaq, Leung, Tiklun, Wang, Yantao, Lin, JingYang, Ng, Alan Man Ching, Li, Yin, Ebadi, Firouzeh, Tress, Wolfgang, Richardson, Giles, Ge, Chuangye, Hu, Hanlin, Karimipour, Masoud, Baumann, Fanny, Tabah, Kenedy, Pereyra, Carlos, Raga, Sonia R., Xie, Haibing, Lira-Cantu, Monica, Khenkin, Mark V., Visoly-Fisher, Iris, Katz, Eugene A., Vaynzof, Yana, Vidal, Rosario, Yu, Guicheng, Lin, Haoran, Weng, Shuchen, Wang, Shifeng, Djurišić, Aleksandra B.

Perovskite solar cells (PSCs) represent one of the most promising emerging photovoltaic technologies due to their high power conversion efficiency. However, despite the huge progress made not only in terms of the efficiency achieved, but also fundamental understanding of the relevant physics of the devices and issues which affect their efficiency and stability, there are still unresolved problems and obstacles on the path toward commercialization of this promising technology. In this roadmap, we aim to provide a concise and up to date summary of outstanding issues and challenges, and the progress made toward addressing these issues. While the format of this article is not meant to be a comprehensive review of the topic, it provides a collection of the viewpoints of the experts in the field, which covers a broad range of topics related to PSC commercialization, including those relevant for manufacturing (scaling up, different types of devices), operation and stability (various factors), and environmental issues (in particular the use of lead). We hope that the article will provide a useful resource for researchers in the field and that it will facilitate discussions and move forward toward addressing the outstanding challenges in this fast-developing field.