The research of Sun group is focused on the photophysics of nanomaterials including nanosheets, nanorods, quantum dots, and carbon dots. The novel properties of the nanomaterials originate at the quantum confinement at the nanometer scale. For instance, tunable and pure-color light emission can be achieved by simply changing the size of quantum dots, which is the science behind the new quantum-dot LED (QLED) TVs made by Samsung. The current research in Sun group aims at the anisotropic nanomaterials with emphasis on nanosheets. The anisotropic confinement of the exciton in nanosheets results in new properties different from isotropic quantum dots, such as slower Auger processes, giant oscillator strength transition, high photoluminescence quantum yield, and low threshold lasing. These new photophysics properties are studied using time-resolved laser spectroscopy and other material characterization methods including electron microscopy, XRD, FTIR, and Raman spectroscopy.
The students in Sun group will learn and master many experimental techniques for nanomaterial research, including electron microscopy (such as TEM and SEM), UV-Vis-IR spectroscopy, laser technology, synthesis of nanostructured materials, optoelectronic device fabrication and testing. In the process of research, they will participate in planning future research and setting up experimental apparatus. In such a way, they will gain significant critical-thinking and problem-solving skills.
- Wenhui Wan, Yugui Yao, Liangfeng Sun, Cheng-Cheng Liu, Fan Zhang, "Topological, Valleytronic, and Optical Properties of Monolayer PbS", Advanced Materials 29, 1604788 (2017)
- Simeen Khan, Zhoufeng Jiang, Shashini M. Premathilka, Antara Antu, Jianjun Hu, Andrey A. Voevodin, Paul J. Roland, Randy J. Ellingson, Liangfeng Sun, "Few-Atom-Thick Colloidal PbS/CdS Core/Shell Nanosheets", Chemistry of Materials28, 5342 (2016)
- Zhoufeng Jiang, Ghadendra B. Bhandari, Shashini M. Premathilaka, Simeen Khan, Douglas M. Dimick, Cody Stombaugh, Angelic Mandell, Yufan He, H. Peter Lu and Liangfeng Sun, "Growth of colloidal PbS nanosheets and the enhancement of their photoluminescence", Phys. Chem. Chem. Phys. 17, 23303 (2015)
- Ghadendra B. Bhandari, Kamal Subedi, Yufan He, Zhoufeng Jiang, Matthew Leopold, Nick Reilly, H. Peter Lu, Alexey T. Zayak and Liangfeng Sun, "Thickness-Controlled Synthesis of Colloidal PbS Nanosheets and Their Thickness-Dependent Energy Gaps", Chemistry of Materials 26, 5433 (2014)
- L. Sun, J. J. Choi, D. Stachnik, A. C. Bartnik, B.-R. Hyun, T. Hanrath, G. G. Malliaras and F. W. Wise " Bright infrared quantum-dot light-emitting diodes through inter-dot spacing control ", Nature Nanotechnology 7, 369 (2012)
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