Stoichiometry and substitution as ways to engineer structure and optoelectronic properties in inorganic perovskite halides

Preethi Meher
Event Speaker
K.R.S. Preethi Meher
Event Speaker Description
Assistant Professor
Department of Materials Science
Central University of Tamilnadu
Event Type
Materials and Devices Seminar Series
Date
Event Location
KEC 1003
Event Description

Perovskites form a broad class of materials and are considered to be technologicaly important for both their  semiconducting and dielectric properties. Cs-based inorganic perovskite halides of composition CsPbX3 where X is an halogen ion (Cl, Br, I), exhibit unique optoelectronic properties and excellent stability compared to their hybrid or inorganic counterparts. These compounds have attracted attention mainly, due to plethora of optoelectronic applications that they can cater to: spanning Light emitting diodes to photodetectors. In this talk, the synthesis, crystal structure and the correlation to the optoelectronic properties of CsPbBr3 in the form of both polycrystalline powders and single crystals will be discussed. In the hydrothermal method employed, the Cs/Pb ratio played a key role in the stabilization of the phase rather than other synthesis conditions like temperature and time. The effect of B-site cationic substitution, by considering  Na and Cd invidually in signficant levels, has been studied. This brought out the challenges in the structure property correlation of such substituted compositions  over those of nanostructures reported in literature. Single crystals of both CsPbBr3 and Na-substituted CsPbBr3 were synthesized using room temperaure anti-solvent route. The investigations done, so far, reflects the poor preference of CsPbBr3 to adopt any substitutional defects under equilibrium conditions.

Speaker Biography

Dr. K.R.S. Preethi Meher is an Assistant Professor at the Department of Materials Science, School of Technology, Central University of Tamilnadu located in Thiruvarur district, India. She completed her Ph.D. at the Materials Research Center, Indian Institute of Science Bengaluru in 2012. She was the Erasmus Mundus-Willpower visiting research fellow at the Laboratoire CNRS SPMS in 2011. She was also a CNRS postdoctoral Researcher at the Laboratoire CRISMAT, Caen from 2013-2014 and later served as a Research Associate at the Materials Science Division of Indira Gandhi Center for Atomic Research, Kalpakkam before joining her current position. Her research laboratory at CUTN focuses on the development of new multifunctional materials and electroceramics for energy production, harvesting, and sensing applications. Currently, she works on synthesis, structural and property correlations involving various lead based and lead free perovskite halide compositions. Currently, she is associated with Boise State University as a the Fullbright Kalam Academic and Professional excellence visiting fellow and studies novel layered perovskite halide compositions that exhibit excellent optoelectronic properties and stability for enhanced lifetime of the photovoltaic device.