Seminar

2020/09/03(Thu)     11:00 -12:00    五樓第一會議室5th Floor(1st meeting room)

Title

Black phosphorus optoelectronics for mid-infrared silicon photonics

Speaker

Dr. Chang-Hua Liu

Institute of Photonics Technologies, National Tsing Hua University

Abstract

Black phosphorus (BP) is an emerging material for mid-infrared optoelectronics, as it owns a direct and narrow band gap (∼0.3 eV in bulk). In addition, because of its van der Waals (vdW) nature, BP based optoelectronics can be easily integrated onto diverse substrates or photonic structures, making them promise for mid-infrared integrated photonics applications. Here, we will outline the architectures of photodetectors using BP based van der Waals (vdW) heterostructures. The performed photodetectors not only can exhibit the features of linear-dichroic, broadband (visible to mid-infrared), high external quantum efficiency and fast operation speed (> 200 MHz) at room temperature, but also can be coupled with a silicon waveguide. Furthermore, we will demonstrate light emitting diodes based on the BP heterostructures, which can emit linearly polarized light (degree of polarization ~75 %) with the emission spectra cover the technologically important mid-infrared atmospheric window (3-4 µm). Via integrating the BP emitter with a silicon waveguide, we further show that its emission can evanescently couple and propagate through the waveguide, showing the usefulness for on-chip mid-infrared light source applications.