High-Performance Flexible Ultraviolet Phototransistor Based on an AlGaN/GaN Heterojunction Membrane.

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Devices

Background:

• Aluminum Gallium Nitride/Gallium Nitride (AlGaN/GaN) high electron mobility transistors (HEMTs) are suitable for ultraviolet photodetectors.
• Existing AlGaN/GaN HEMT photodetectors are rigid, limiting flexible and wearable applications.

Purpose of the Study:

• To develop a flexible AlGaN/GaN HEMT-based ultraviolet photodetector.
• To enable new applications in flexible and wearable optoelectronics.

Main Methods:

• Fabricated a flexible photo-high electron mobility transistor (photo-HEMT) by releasing an AlGaN/GaN membrane from an AlGaN/GaN-on-insulator.
• Transferred the AlGaN/GaN membrane onto a flexible substrate.

Main Results:

• Achieved excellent optoelectronic performance with a detectivity of 2.7 × 10¹⁶ Jones at 360 nm wavelength.
• The flexible photo-HEMT outperforms previously reported three-terminal flexible phototransistors.
• Demonstrated potential for performance enhancement via the strain-induced piezo-photonic effect.

Conclusions:

• The development of a flexible AlGaN/GaN photo-HEMT is a significant advancement for flexible phototransistors.
• Compatibility with existing Gallium Nitride (GaN) technology facilitates the commercialization of flexible optoelectronics.