2020/04/17 by Leonardo Viti, David G. Purdie, Antonio Lombardo +2
Engineering · Physics and Astronomy · #Boron nitride #Dynamic range #Electronic engineering #Graphene #Materials science #Nanotechnology #Noise (video) #Noise-equivalent power #Optics #Optoelectronics #Photodetector #Physics #Responsivity #Sensitivity (control systems) #Superconducting and THz Device Technology #Terahertz radiation #Terahertz spectroscopy and technology #Terahertz technology and applications #Thermal Radiation and Cooling Technologies #cond-mat.mes-hall #physics.app-ph
paper · pdf · doi:10.1021/acs.nanolett.9b05207
This is the unedited authors' version of the submitted article, published in its final form at http://dx.doi.org/10.1021/acs.nanolett.9b05207 16 Pages, 4 Figures
openalex publication_date 2020/04/17 · arxiv created 2020/04/21 · arxiv updated 2020/06/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Uncooled terahertz photodetectors (PDs) showing fast (ps) response and high sensitivity (noise equivalent power (NEP) < nW/Hz 1/2 ) over a broad (0.5–10 THz) frequency range are needed for applications in high-resolution spectroscopy (relative accuracy ∼10 –11 ), metrology, quantum information, security, imaging, optical communications. However, present terahertz receivers cannot provide the required balance between sensitivity, speed, operation temperature, and frequency range. Here, we demonstrate uncooled terahertz PDs combining the low (∼2000 k B μm –2 ) electronic specific heat of high mobility (>50 000 cm 2 V –1 s –1 ) hexagonal boron nitride-encapsulated graphene, with asymmetric field enhancement produced by a bow-tie antenna, resonating at 3 THz. This produces a strong photo-thermoelectric conversion, which simultaneously leads to a combination of high sensitivity (NEP ≤ 160 pW Hz –1/2 ), fast response time (≤3.3 ns), and a 4 orders of magnitude dynamic range, making our devices the fastest, broad-band, low-noise, room-temperature terahertz PD, to date.