סמינר מחלקה אלקטרוניקה פיזיקאלית: Yonatan Calahorra
Piezoelectricity at the Nanoscale:
Methods, Materials and Applications
By:
Dr. Yonatan Calahorra
Department of Materials Science and Metallurgy, University of Cambridge
Abstract
Recent conceptual developments in communication (e.g. Internet-of-Things) and healthcare (e.g. electroceuticals, digital healthcare) drive the need to develop applications such as highly efficient or self-powered sensors, and the smart/functional materials to enable them. In this talk I will revisit the established notion of piezoelectricity from a fresh perspective, focused on nanoscale, non-ceramic materials.
Nanoscale electromechanical materials offer advantages compared to bulk due to enhanced surface area and flexibility. Nonetheless, characterization at the nanoscale is challenging due to practical limitations of existing methods and co-existence of different electromechanical effects. I will present new atomic force microscopy (AFM) methodologies I developed specifically to overcome existing limitations, and for disambiguation in understanding nanoscale electromechanical current generation. I will show their application to probe piezoelectricity in materials previously inaccessible by standard piezoelectric AFM methods. e.g., correlating crystalline structure and piezoelectric response in III-V semiconductor nanowires. Next, I will present the use of nanostructured piezoelectric semiconductors as electromechanical sensors/energy harvesters, and in particular the piezotronic effect – a unique feature of piezoelectric semiconductors. I will discuss fundamental and practical aspects in achieving efficient electromechanical coupling.
Nanoscale electromechanical materials offer a breadth of effects and functionalities, as demonstrated by these results. I will share potential uses and the research directions inspired by non-conventional piezoelectric nanomaterials serving as an infrastructure for smart/functional materials beneficial applications.
On Thursday, Dec 26th, 2019, 15:00
Room 011, Kitot building
