Infrared avalanche photodiodes from bulk to 2D materials

Area of Science:

• Optoelectronics and Photonics
• Materials Science
• Semiconductor Devices

Background:

• Avalanche photodiodes (APDs) are crucial for optical communication systems due to their high sensitivity and fast response times.
• Traditional APDs based on bulk materials face limitations such as high dark currents, restricting their performance, especially for sensitive applications.

Purpose of the Study:

• To review the evolution and recent developments in Avalanche Photodiodes (APDs) across various material systems.
• To explore novel materials, including superlattices (SLs) and two-dimensional (2D) materials, as alternatives for infrared (IR) APDs.
• To highlight the potential of 2D materials in overcoming the performance limitations of conventional APDs.

Main Methods:

• Analysis of the fundamental operating principles and architectural advancements in APDs.
• Review of material properties enabling high gain and low excess noise across different wavelength ranges.
• Focus on recent progress in III-V, II-VI, superlattice, and 2D material-based IR APDs.

Main Results:

• APD evolution has led to improved bandwidth, reduced noise, and higher gain-bandwidth products.
• III-V APDs, such as AlInAsSb, show promise for future optical communications.
• Type-II superlattices (T2SLs) and 2D materials offer significant potential, particularly in suppressing dark currents for enhanced sensitivity and single-photon detection.

Conclusions:

• Atomically thin 2D materials present a viable alternative to traditional III-V APD technologies, offering a path to high-performance devices.
• 2D APDs demonstrate remarkable performance, including high responsivity and gain, with significantly suppressed dark currents.
• The development of 2D APDs provides a promising approach for fabricating sensitive, low-noise devices for visible to mid-wavelength infrared applications.