Black phosphorus (BP), a narrow band gap semiconductor
without
out-of-plane dangling bonds, has shown promise for broadband and integrable
photodetector applications. Simultaneously exhibiting high speed and
high-efficiency operation, however, remains a critical challenge for
current BP-based photodetectors. Here, we demonstrate a photodetector
based on the BP-based van der Waals heterostructures. The developed
photodetector enables broadband responses in the visible to mid-infrared
range with external quantum efficiency ranging from 20 to 52% at room
temperature. These results together with noise measurements indicate
that the photodetector can detect light in the picowatt range. Furthermore,
the demonstrated BP detector has ultrafast rise (1.8 ns) and fall
(1.68 ns) times, and its photoresponse exhibits reproducible switching
behavior even under consecutive and rapid light intensity modulations
(2100 cycles, 200 MHz), as indicated by the eye-diagram measurement.
By leveraging these features, we show our BP heterostructures can
be configured as a point-like detector in a scanning confocal microscopy,
useful for mid-infrared imaging applications.
Visual acuity can be improved with perceptual learning and patching in older children and adult patients with anisometropic amblyopia. The improvements in visual acuity achieved with patching were one line better than those achieved with perceptual learning. Perceptual learning might provide an alternative treatment in patients with anisometropic amblyopia.
Light-emitting
diodes (LEDs) based on III–V/II–VI
materials have delivered a compelling performance in the mid-infrared
(mid-IR) region, which enabled wide-ranging applications in sensing,
including environmental monitoring, defense, and medical diagnostics.
Continued efforts are underway to realize on-chip sensors via heterogeneous
integration of mid-IR emitters on a silicon photonic chip, but the
uptake of such an approach is limited by the high costs and interfacial
strains, associated with the processes of heterogeneous integrations.
Here, the black phosphorus (BP)-based van der Waals (vdW) heterostructures
are exploited as room-temperature LEDs. The demonstrated devices emit
linearly polarized light, and the spectra cover the technologically
important mid-IR atmospheric window. Additionally, the BP LEDs exhibit
fast modulation speed and exceptional operation stability. The measured
peak extrinsic quantum efficiency is comparable to the III–V/II–VI
mid-IR LEDs. By leveraging the integrability of vdW heterostructures,
we further demonstrate a silicon photonic waveguide-integrated BP
LED.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.