Room-Temperature Ultrabroadband Photodetection with MoS₂ by Electronic-Structure Engineering Strategy

Area of Science:

• Materials Science
• Optoelectronics
• Solid State Physics

Background:

• Broadband photodetection is crucial for optical information processing.
• Current limitations in mid-infrared (mid-IR) photodetection at room temperature (RT) hinder technological advancement.
• High dark currents in narrow-bandgap semiconductors impede RT operation.

Purpose of the Study:

• To propose an electronic-structure strategy for designing ultrabroadband photodetection materials operating at RT.
• To engineer layered MoS2 with a modulated bandgap and electronic state density for enhanced photodetection.
• To demonstrate RT photodetection across visible to far-infrared spectrum.

Main Methods:

• Utilized an electronic-structure strategy to design novel photodetection materials.
• Engineered layered MoS2 by introducing defect energy levels.
• Achieved a bandgap of 0.13 eV and modulated electronic state density in MoS2.

Main Results:

• Demonstrated RT photodetection for wavelengths ranging from 445 nm to 9.5 µm.
• Achieved a peak photoresponsivity of 21.8 mA W⁻¹ in the mid-IR region, the highest reported value.
• Observed electronic state density-dependent photoresponsivity.

Conclusions:

• The engineered layered MoS2 is a promising candidate for ultrabroadband RT optoelectronic devices.
• The proposed strategy offers inspiration for designing new optoelectronic materials.
• Overcoming RT mid-IR photodetection limitations is key for future technologies.