Department of Chemistry
Wednesday September 11, 2019
+Amol Ajinkya Memorial Fund Lecture
Two-dimensional (2D) metal halide perovskites have made an impressive entry in the field of solar cells and LEDs as highly promising semiconductors. They feature a high degree of structural flexibility and tunable optoelectronic properties. They have a general formula of (A’)2(A)n-1MnX3n+1, where A = Cs+, CH3NH3+ (MA), HC(NH2)2+ (FA), M = Ge2+, Sn2+, Pb2+ and X = Cl-, Br-, I-, are the perovskite components and A’+ = RNH3 is an organic spacer. There are four kinds of 2D organic inorganic hybrid perovskites so far: Ruddelsden-Popper, Cation-ordered, Jacobson-Dion and Diammonium Cation. These vary from one another in ways the inorganic slabs stack and the way the spacer cations interact with the inorganic slabs. Generally, 2D perovskites form from solution via the bottom-up self-assembly of individual, semiconducting perovskite sheets having an adjustable slab thickness of up to few nanometers, separated by insulating bulky organic molecules. As a result, they behave as natural multiple quantum wells (QWs) with the semiconducting perovskite layers representing the wells and the insulating organic spacers representing the barriers. The width of the barrier is fixed and depends only on the length of the A’ cation, while the width of the well can be adjusted by varying the thickness of perovskite slabs, which is defined by the n variable in (A’)2(A)n-1MnX3n+1. It is critical to understand the thermodynamic and chemical limitations of the maximum layer thickness that can be sandwiched between the organic bilayers while retaining the structural integrity of the 2D perovskite.
Mercouri G Kanatzidis was born in Thessaloniki Greece in 1957. He has a Bachelor of Science degree from Aristotle University in Greece. He received his PhD degree in chemistry from the University of Iowa in 1984. He was a postdoctoral fellow at the University of Michigan and Northwestern University from 1985 to 1987. He currently is a Charles E and Emma H Morrison Professor in Chemistry at Northwestern University.
Kanatzidis has been named a Presidential Young Investigator by the National Science Foundation, an Alfred P Sloan Fellow, a Beckman Young Investigator, a Camille and Henry Dreyfus Teaching Scholar, a Guggenheim Fellow and in 2003 was awarded the Alexander von Humboldt Prize. In 2014 he received the Einstein Professor Award, Chinese Academy of Sciences, the International Thermoelectric Society Outstanding Achievement Award; and the MRS Medal. In 2016 he also won the Samson Prime Minister's 1M Prize for Innovation in Alternative Fuels for Transportation, 2016 American Chemical Society’s James C. McGroddy Prize for New Materials, American Chemical Society’s Award in Inorganic Chemistry and in 2015 the ENI Award for the "Renewable Energy Prize" and Royal Chemical Society’s De Gennes Prize. American Institute of Chemistry Chemical Pioneer Award 2018. He is a Fellow of the Royal Society of Chemistry.