Abstract:

Electron paramagnetic resonance (EPR) is a very powerful method due to its enhanced sensitivity to unpaired electrons. In order to understand the defect structure in functional nano-materials we use multi-frequency EPR spectroscopy. In this presentation i) basics of EPR spectroscopy, ii) quantum confinement effects in ferroelectric nano-materials and iii) EPR and Photoluminescence (PL) investigations of intrinsic defect centers in semiconductor zinc oxide (ZnO) nanoparticles will be given. Starting with the introductory information about EPR spectroscopy; poling, aging, doping and nano-size effects will be discussed for the ferroelectric materials such as, PbTiO3, BaTiO3, PbZrTiO3 (PZT) etc. In the last part of the talk, surface and core defects and their reactivity under temperature and light will be presented for ZnO semiconductor nano-materials. Defect models will be discussed.

Short Biography of the Speaker:

Dr. Emre Erdem is associate professor at Sabanci University, Faculty of Engineering and Natural Sciences, Materials Science and Nano Engineering program (Istanbul/Turkey). He finished his BSc degree in Physics in Ankara University (1998). He obtained his MSc and PhD degree in experimental Physics in University of Leipzig (2001-2006). He did his postdoctoral studies at Technical University of Darmstadt in Materials Science. In 2010, he became a research group leader in the Institute of Physical Chemistry at the University of Freiburg on the spectroscopic studies of functional nanomaterials. He has a strong background in diverse fields, such as materials physics and chemistry, physical chemistry, atomic physics, solid-state physics, defect chemistry, studies of electronic properties of energy materials and the synthesis and characterization of nanocrystals (functional nanomaterials, piezoelectrics, supercapacitors and, in particular, semi-conducting quantum dots). He was awarded LE STU IUM/Marie Skłodowska-Curie Research Fellowship (2017), Eugen Grätz Prize (2011) and DAAD scholarship (1999). He (co-) authored more than 70 publications ininternational journals and more than 50 communications in international conferences.