Scalable Fabrication of Atomically Thin Monolayer MoS2 Photodetectors

Abstract

Scalable fabrication of high quality photodetectors derived from synthetically grown monolayer transition metal dichalcogenides is highly desired and important for wide range of nanophotonics applications. We present here scalable fabrication of monolayer MoS2 photodetectors on sapphire substrates through an efficient process, which includes growing large scale monolayer MoS2 via chemical vapor deposition (CVD), and multi-step optical lithography for device patterning and high quality metal electrodes fabrication. In every measured device, we observed the following universal features: (i) negligible dark current $(I_{dark}⩽10fA)$; (ii) sharp peaks in photocurrent at $\sim$1.9eV and $\sim$2.1eV attributable to the optical transitions due to band edge excitons; (iii) a rapid onset of photocurrent above $\sim$2.5eV peaked at $\sim$2.9eV due to an excitonic absorption originating from the van Hove singularity of MoS${}_2$. We observe low ($⩽300\%$) device-to-device variation of photoresponsivity. Furthermore, we observe very fast rise time $\sim$0.5 ms, which is three orders of magnitude faster than other reported CVD grown 1L-MoS${}_2$ based photodetectors. The combination of scalable device fabrication, ultra-high sensitivity and high speed offer a great potential for applications in photonics.

4 pages, 3 figures

References in corpus (11)

• 2D materials and van der Waals heterostructures
• Anomalous Lattice Vibrations of Single and Few-Layer MoS2
• Two-Dimensional Material Nanophotonics
• Phonon and Raman scattering of two-dimensional transition metal dichalcogenides from monolayer, multilayer to bulk material
• Strong light-matter coupling in two-dimensional atomic crystals
• Photocurrent generation with two-dimensional van der Waals semiconductors
• Large and tunable photo-thermoelectric effect in single-layer MoS2
• Photoconductivity of biased graphene
• Probing excitonic states in ultraclean suspended two-dimensional semiconductors by photocurrent spectroscopy
• Nonlinear Photoluminescence in Atomically Thin Layered WSe2 Arising from Diffusion-Assisted Exciton-Exciton Annihilation
• MoS2 Nanoribbon Transistors: Transition from Depletion-mode to Enhancement-mode by Channel Width Trimming

Cited by in corpus (3)

• Photoresponsivity enhancement in monolayer MoS${}_2$ by rapid O${}_2$:Ar plasma treatment
• Local photodoping in monolayer MoS2
• Semimetal-Monolayer Transition Metal Dichalcogenides Photodetectors for Wafer-Scale Ultraviolet Photonics