Multilayer WSe₂ /MoS₂ Heterojunction Phototransistors through Periodically Arrayed Nanopore Structures for Bandgap...

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• 2D transition metal dichalcogenides (TMDs) show promise for optoelectronics.
• Multilayered TMD photodetectors face limitations like indirect bandgaps and short carrier lifetimes.

Purpose of the Study:

• To improve the efficiency of multilayered p-WSe2/n-MoS2 phototransistors using periodically arrayed nanopore structures (PANS).
• To investigate the impact of PANS on the photodetector figures of merit for WSe2/MoS2 heterostructures.

Main Methods:

• Density functional theory (DFT) calculations.
• Photoluminescence (PL) and time-resolved photoluminescence (TRPL) measurements.
• Fabrication and characterization of p-WSe2/n-MoS2 heterojunction phototransistors with and without PANS.

Main Results:

• PANS significantly enhance the responsivity and detectivity of multilayered p-WSe2/n-MoS2 phototransistors.
• Devices with PANS exhibit responsivity of 1.7 × 10^4 A/W and detectivity of 1.7 × 10^13 Jones.
• Performance improvements are nearly two orders of magnitude higher compared to pristine devices.

Conclusions:

• Periodically arrayed nanopore structures are effective in enhancing the optical properties of WSe2/MoS2 heterojunctions.
• This approach represents a significant advancement for next-generation optoelectronic applications.
• The study highlights the potential of nanostructuring for overcoming limitations in TMD-based photodetectors.