Ultrafast Graphene Light Emitters

• DOI: 10.1021/acs.nanolett.7b04324
• Publication Date: 2018-01-16T20:40:44Z
• Authors: Young Duck Kim; Yuanda Gao; Ren-Jye Shiue; Lei Wang; Burak Aslan; Myung-Ho Bae; Hyungsik Kim; Dongjea Seo; Heon-Jin Choi; Suk Hyun Kim; Andrei Nemilentsau; Tony Low; Cheng Tan; Dmitri K. Efetov; Takashi Taniguchi; Kenji Watanabe; Kenneth L. Shepard; Tony F. Heinz; Dirk Englund; James Hone
• Keywords: Nanophotonics

Ultrafast electrically driven nanoscale light sources are critical components in nanophotonics. Compound semiconductor-based for the nanophotonic platforms have been extensively investigated over past decades. However, monolithic ultrafast with a small footprint remain challenge. Here, we demonstrate graphene emitters that achieve pulse generation up to 10 GHz bandwidth across broad spectral range from visible near-infrared. The fast response results charge-carrier dynamics and weak electron-acoustic phonon-mediated coupling between electronic lattice degrees of freedom. We also find encapsulating hexagonal boron nitride (hBN) layers strongly modifies emission spectrum by changing local optical density states, thus providing 460% enhancement compared gray-body thermal radiation peak centered at 720 nm. Furthermore, hBN encapsulation permit stable bright temperatures 2000 K under ambient conditions as well efficient cooling via near-field hybrid polaritonic modes electrical excitation. These high-speed provide promising path on-chip communications other optoelectronic applications.