יום חמישי, ה – 7 בספטמבר 2023 בשעה 14:30
אודיטוריום ע"ש דויד וואנג, בניין מידן, קומה 3
Mr. Orr Be'er – PhD candidate
Department of Materials Science and Engineering Technion – Israel Institute of Technology, Haifa
Scintillators are materials that convert ionizing radiation into visible light. They serve a wide array of functions in high-energy detection and characterization, spanning from particle accelerators and space exploration to medical imaging devices and homeland security applications. The study of scintillators primarily revolves around discovering novel crystalline materials for scintillation, improving the crystal growth process, and identifying new efficient light-emitting dopants.
This work investigates the manipulation of scintillation properties using metamaterials— material compositions that can be tailored to enhance their scintillation characteristics. The first part of the presentation explores the scintillation properties of polymer-based multi-layered nanostructures that incorporate two distinct layers: a standard polymer scintillator layer and a polymer-titanium hybrid layer. I will show how the absorption of x-rays by the dense polymer-hybrid layer enables the transfer of energy to the scintillator material and enhances light emission.
The second part of the talk will focus on collective cathodoluminescence from structures made of CsPbBr3 nanocrystals. I will first show that the photoluminescence from the ordered structure of nanocrystals exhibits superfluorescence: a burst of short and intense. Then, I will show the fast dynamic of collective emission triggered by free electrons. I will show how an electron beam affects the type of emission and discuss the limitation of collective emission.