High-performance self-powered broadband photodetector based on a PtS₂/MoSe₂ vertical heterostructure

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Broadband photodetectors are crucial for environmental monitoring, biomedicine, remote sensing, imaging, and optical communications.
• Existing photodetectors often require external bias, leading to reduced energy efficiency and slower response times.
• Self-powered photodetectors eliminate the need for external bias, improving performance and energy efficiency.

Purpose of the Study:

• To demonstrate a self-powered photodetector based on a PtS₂/MoSe₂ van der Waals heterostructure.
• To leverage the type-II band alignment for efficient carrier separation without external bias.
• To evaluate the device's performance in terms of dark current, spectral response, responsivity, detectivity, and imaging capabilities.

Main Methods:

• Fabrication of a PtS₂/MoSe₂ van der Waals heterostructure.
• Characterization of the heterostructure's type-II band alignment.
• Measurement of photodetector performance under various wavelengths and zero bias.
• Assessment of imaging capabilities across the visible-infrared spectrum.

Main Results:

• The PtS₂/MoSe₂ photodetector exhibits an ultralow dark current of approximately 10^-13 A.
• The device demonstrates a broadband response from 405 nm to 1064 nm.
• Under 532 nm excitation and zero bias, the photodetector achieves a responsivity of 0.22 A W^-1, a specific detectivity of 5.7 × 10⁹ Jones, and an external quantum efficiency of 50.4%.
• High-quality imaging was achieved across the visible-infrared spectrum.

Conclusions:

• The PtS₂/MoSe₂ heterostructure serves as a robust platform for self-powered, broadband photodetectors.
• The developed device offers high sensitivity, stability, and low power consumption.
• This technology holds promise for advanced multispectral sensing and imaging applications.