Gate tunable self-powered few-layer black phosphorus broadband photodetector

Area of Science:

• Materials Science
• Condensed Matter Physics
• Optoelectronics

Background:

• Few-layer black phosphorus (BP) exhibits unique optoelectronic properties.
• The giant Stark effect in BP offers potential for novel device applications.
• Developing efficient and tunable photodetectors remains a key challenge in optoelectronics.

Purpose of the Study:

• To theoretically propose a broadband photodetector based on few-layer black phosphorus.
• To investigate the self-powered operation and tunable photodetection range using a gate-induced Stark effect.
• To explore the polarization sensitivity and anisotropic photoresponse of the proposed device.

Main Methods:

• Atomic first-principles calculations were employed to model the device.
• A vertical gate voltage was applied to break the inversion symmetry of few-layer BP.
• The photogalvanic (or photovoltaic) effect (PGE) was analyzed for photocurrent generation.

Main Results:

• A self-powered broadband photodetector was theoretically proposed, operating without external bias.
• The gate-induced giant Stark effect enabled tunable photodetection from mid-infrared to far-infrared ranges.
• High polarization sensitivity (extinction ratio up to 10^4) and anisotropic photoresponse were predicted.

Conclusions:

• Few-layer black phosphorus is a promising material for self-powered, tunable broadband photodetectors.
• The gate-induced giant Stark effect provides a mechanism for precise control over photodetection range.
• The proposed device offers a feasible pathway for advanced optoelectronic applications.