Highly Sensitive, Gate-Tunable, Room-Temperature Mid-Infrared Photodetection Based on Graphene–Bi₂Se₃ Heterostructure

Abstract

Broadband detection of mid-infrared (IR) photons extends to advanced optoelectronic applications such as imaging, sensing, and telecommunications. While graphene offers an attractive platform for broadband visible/IR photodetection, previous efforts to improve its responsivity, for example, by integrating light-absorbing colloids or waveguide or antenna fabrication, were achieved at the cost of reduced photon detection bandwidth. In this work, we demonstrate room-temperature operation of a novel mid-IR photodetector based on a graphene−Bi 2 Se 3 heterostructure showing broadband detection and high responsivity (1.97 and 8.18 A/W at mid-and near-IR, respectively), in which simultaneous improvement of the spectral range and responsivity is achieved via exploiting broadband absorption of mid-IR and IR photons in a small-band-gap Bi 2 Se 3 topological insulator and efficient hot carrier separation and strong photogating across the Bi 2 Se 3 /graphene interface. With sufficient room for further improvement by interface engineering, our results show a promising route to realize ultrabroadband, high-responsivity hot-carrier optoelectronics at room temperature.

2D Layered Material‐Based van der Waals Heterostructures for Optoelectronics

“…Broadband photodetection is vital in many important optoelectronic applications such as communication and imaging . Most broadband photodetectors reported are based on graphene or BP with narrow bandgaps, while poor photoresponsivities are usually observed due to the ultralow efficiency of the photoexcited electron and hole pairs . Recently, Miao and co‐workers demonstrated an atomically thin heterostructure based on WSe 2 –graphene–MoS 2 with sandwich structure ( Figure a).…”

Bilayer graphene/HgCdTe based very long infrared photodetector with superior external quantum efficiency, responsivity, and detectivity

“…To the best of our knowledge, the obtained results for the proposed photodetector are better than that of previously reported graphene based photodetectors. 1,3,29,30,33,37,39,43,[82][83][84][85][93][94][95][96][97][98][99][100][101][102][103] Table 2 summarizes the key parameters of our proposed device with other MCT and graphene based photodetectors reported earlier.…”

Graphene Based Waveguides

“…However, it's difficult to fabricate these materials which are challenging to operate at room temperature till now. Choi's group [61] integrated graphene with a Bi 2 Se 3 heterostructure, in which graphene functioned as high mobility charge transport layers and Bi 2 Se 3 functioned as a broadband IR absorber supplying holes in graphene. The graphene-Bi 2 Se 3 structure showed broadband absorption and high-intensity response at room temperature.…”