Dr. Qing Tu

Zoom Link: bit.ly/MAE-seminar-FA22
Meeting ID: 951 7890 2068
Passcode: MAE22fall

Two-dimensional (2D) metal halide perovskites (MHPs) are emerging low-cost, high performance semiconductor materials with great promises in optoelectronics and other semiconductor devices. Mechanical strain is ubiquitous in these materials during device fabrication and operation, which could induce stability issues and/or impact the device performance. This calls for a comprehensive understanding of the mechanical behaviors of 2D MHPs. In this talk, I will present a series nanomechanical studies by scanning probe techniques to elucidate the intrinsic mechanical behaviors of 2D MHPs along the in-plane direction and how extrinsic factors in a typical device operational environment can affect these mechanical behaviors. I will first establish a fundamental structure-property understanding of 2D HOIPs regarding their elastic behavior. I will further show the abnormal thermo-mechanical behavior of these materials and the fundamental mechanism behind the anomaly. Finally, I discuss the fatigue failure behavior of 2D HOIPs under subcritical cyclic loading conditions.

Dr. Qing Tu is an assistant professor in the Department of Materials Science & Engineering at Texas A&M University (TAMU). He received his B.S. in Theoretical & Applied Mechanics from Peking University in 2011 and PhD in Mechanical Engineering & Materials Science with Outstanding Dissertation Award from Duke University in 2017. During his PhD, he also obtained a certificate (minor) in Nanoscience and M.A. in Economics. He then did a postdoc in the Department of Materials Science & Engineering at Northwestern University, during which he was selected as a recipient of American Vacuum Society Electronic Materials & Photonics Division Postdoctoral Travel Award in 2019. He is interested in understanding and engineering the surfaces and interfaces in advanced functional materials (e.g., 2D materials, hybrid organic-inorganic perovskites) from a mechanics perspective to design and optimize their functional properties for applications. He won the ACS Petroleum Research Fund Doctoral New Investigator award and ASME Robert M. and Mary Haythornthwaite Young Investigator Award in 2021.