学术活动

学术活动

学术讲座:Light-matter Interactions in 2D Materials and Device Applications

发表时间:2019-05-24

  报告题目:Light-matter Interactions in 2D Materials and Device Applications

  报告时间:2019年5月24日(周五)下午15:00

  报告地点:综合楼416会议室

  报 告 人:鲍桥梁 教授

  Abstract:Our research interests are mainly focused on the light-matter interactions in 2D materials in the forms of nonlinear light absorption, light modulation (amplitude, phase and polarisation), photo-electrical conversion, wave-guiding and polaritonic behaviours. This talk will give an overview of photonic and optoelectronic device applications based on these optical phenomena in 2D materials [1-4]. Firstly, to overcome the limit light absorption in graphene and obtain large nonlinear optical modulation depth, we developed a serial of new saturable absorbers based on graphene heterostructures and other 2D materials, including graphene/Bi2Te3 [5], black phosphorus [6] and self-doped plasmonic 2D Cu3-xP nanosheets [7] as well as 2D halide perovskite [8]. Secondly, in order to fabricate improved graphene photodetectors working in different spectral ranges, we integrated graphene with other 2D materials with variant electronic structures, for example, graphene/perovskite for visible light detection [9], graphene/MoTe2 [10] and graphene/Cu3-xP for near infrared light detection [11], and graphene-Bi2Te3 for broadband infrared light detection [12]. By fine tuning or aligning the electronic structure, we are able to engineer the photo-gating effect [13] and depletion width in 2D material heterostructures, such as graphene/WS2, MoS2/WS2 and WSe2/WS2 heterojunction [14], monolayer-bilayer WSe2 heterojunction [15] and 2D perovskite p-n junction [16], so as to achieve higher quantum efficiency, photo-responsivity and large photo-active area. Lastly, the THz light modulations associated with plasmonic excitation in graphene/Bi2Te3, topological insulator Bi2Te3, graphene nanoribbon and 3D graphene were investigated using either spectroscopic or real space imaging techniques [17-20]. We developed a surface plasmon resonance (SPR) sensor using antimonene materials, and found that such a sensor using new, more sensitive materials to look for key markers of disease in the body increased detection by up to 10,000 times. [19] In particular, we update our recent progress on the observation of anisotropic and ultra-low-loss polariton propagation along the natural vdW material α-MoO3.[20] In summary, the advances of optical researches in 2D materials may pave the way for the next generation photonic and optoelectronic device applications.