MMAE Seminar - Dr. Mercouri Kanatzidis - Design of New Semiconductors for the Detection of X-ray and Gamma-radiation

Armour College of Engineering's Mechanical, Materials & Aerospace Engineering Department will welcome Dr. Mercouri G. Kanatzidis, Charles E. and Emma H. Morrison Professor of Chemistry at Northwestern University, on Wednesday, March 1st, to present his lecture, Design of New Semiconductors for the Detection of X-ray and Gamma-radiation.

Abstract

In the field of room temperature radiation detection, considerable effort have been poured into developing new radiation sensitive material. CdTe and CdTe-based compounds, such as CdZnTe, have been considered the most promising RT detection materials, however, the high cost of their commercial detectors severely limits their broad application. Due to either growth difficulties, handling issues or cost, only few other compounds, mainly binary halides, such as HgI2, TlBr, and, PbI2, which have been developed for the application of X-ray and γ ray spectrometers, suffer from mechanical and polarization problems. Therefore, there is an increasing demand to explore new materials with promising detection properties. I will present the scientific basis for the chemical design and selection of new semiconductor detector materials and our recent successes in identifying very promising new systems. One example is Cs2Hg6S7 which crystallizes in the space group P42nm, and has a high density of 6.94 g·cm-3. The high atomic number and high density means a high stopping power for X and γ ray radiation. The band gap of Cs2Hg6S7 crystal is direct at 1.63 eV. Other systems include Hg3Se2X2 (X= Cl, Br, Te) and CsPbBr3. In order to fulfill the basic requirement for room temperature radiation detection, special attention is given to increasing the resistivity by improving the crystal growth process. Also, the secondary competing phases are being studied to avoid their formation. Finally, the optical and electrical properties are measured.

Biography

Mercouri Kanatzidis was born in Thessaloniki, Greece. After obtaining a B.Sc. from Aristotle University in Greece, he received his Ph.D. in chemistry from the University of Iowa in 1984. He was a post-doctoral research associate at the University of Michigan and Northwestern University from 1985 to 1987 and is currently the Charles E. and Emma H. Morrison Professor of Chemistry at Northwestern University. Mercouri moved to Northwestern in the fall of 2006 from Michigan State University where he was a University Distinguished Professor of Chemistry since 1987.

Mercouri also holds an appointment at Argonne National Laboratory and is the editor-in-chief of the Journal of Solid State Chemistry.