Electrically Tunable Exciton and Telecom-Band Light-Emitting Diodes in Few-Layer Phosphorene

Area of Science:

• Materials Science
• Condensed Matter Physics
• Optoelectronics

Background:

• Two-dimensional (2D) semiconductors with direct band gaps are promising for ultrathin light-emitting diodes (LEDs).
• Existing 2D semiconductor LEDs primarily operate in the visible spectrum, limiting their use in near-infrared (NIR) telecommunication and optical computing.
• Black phosphorus (BP) is a 2D material with a direct band gap, suitable for NIR applications.

Purpose of the Study:

• To demonstrate NIR LEDs using bilayer and trilayer phosphorene.
• To investigate the influence of electrical fields on bright excitons in few-layer phosphorene.
• To achieve dynamic control over exciton types and emission wavelengths in a single phosphorene-based LED.

Main Methods:

• Fabrication of LEDs using bilayer and trilayer black phosphorus (BP).
• Application of electrical field regulation to control bright excitons.
• Dynamic adjustment of carrier injection conditions to tune emission properties.

Main Results:

• Successful demonstration of NIR light emission from bilayer and trilayer phosphorene LEDs.
• Revealed layer-number-sensitive electrical field regulation of bright excitons.
• Achieved dynamic control of exciton types and emission wavelengths (near 1500 nm) in a single trilayer phosphorene LED by manipulating electric fields and carrier injection.

Conclusions:

• Few-layer black phosphorus (BP) is a viable material for NIR light-emitting diodes (LEDs).
• Electrical field and carrier injection offer dynamic control over emission properties in BP-based LEDs.
• These findings highlight the potential of 2D semiconductors for miniaturized NIR light sources in telecommunication and optical computing.