June 16th (Thu) Graduate Seminar / Proffessor Philippe Guyot-Sionnest

Infrared Colloidal Quantum Dots

The visibility of the colloidal quantum dots (CQD) community greatly improved after the commercial success of QD-LED TV spioneered by Samsung and Sony. This application in the visible spectrum took about 20 years after the first bright CdSe/ZnScore/shells. In my opinion, infrared CQDs will become even more interesting because there is no conceivable competition from organics.

Indeed, infrared CQDs imagers are being increasingly studied in industry and academia. I will describe the HgTe mid-infrared CQDs and progress/issues with device performance.

Prior to HgTe, our focus was on the intraband transition of CQDs. These transitions promised wide flexibility of the semiconductor material, and their study led to basic advances in carrier doping, ohmic conductivity in CQD films, and the understanding of the phonon bottleneck.

Around 2014, the observation of wide gap CQDs with stable and strong infrared resonance rekindled interest in the intraband transitions. Detector performances are still much worse than for interband transitions and this is a challenge, but there are some "bright" prospects.

Biography

1991-Present Professor of Chemistry and Physics at the University of Chicago and the James FranckInstitute, USA

1988-1991:Research scientist, Laboratoire pour l'Utilisation du Rayonnement Electromagnetique(LURE). Universite Paris-Sud, Orsay, France

1987 PhD. in Physics University of California at Berkeley, USA