Interfacial diffusion enabled broadband response in photodetector based on In₂Se₃/GaAs heterojunction

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Infrared (IR) photodetectors are vital components in numerous modern technologies.
• Their performance is often limited by material properties and fabrication complexity.
• Developing broadband photodetectors with high sensitivity and low noise is an ongoing challenge.

Purpose of the Study:

• To develop high-performance In2Se3/GaAs interdiffusion heterostructure photodetectors.
• To achieve a broadband spectral response using a liquid-phase method.
• To characterize the photodetector's performance, including noise, responsivity, and detectivity.

Main Methods:

• Fabrication of In2Se3/GaAs heterostructures via a liquid-phase method.
• Utilizing interdiffusion to form an InGaAs layer at the interface.
• Characterization of the photodetector's spectral response from 0.45 to 2.7 µm.
• Measurement of noise equivalent power, photoresponsivity (R), and detectivity (D*) at various wavelengths and conditions.

Main Results:

• Successful development of In2Se3/GaAs interdiffusion heterostructure photodetectors.
• Broadband detection capability spanning 0.45 to 2.7 µm.
• Achieved a low noise equivalent power of 6.21 × 10⁻¹⁵ WHz⁻¹/² at 1000 Hz.
• Demonstrated high photoresponsivity (16.22 mA/W) and detectivity (4.01 × 10¹¹ Jones) at 630 nm and 0 V.
• Obtained a responsivity of 0.43 µAW⁻¹ and detectivity of 1.07 × 10⁸ Jones at 1550 nm and 0 V.

Conclusions:

• The interdiffused In2Se3/GaAs heterostructure exhibits excellent performance for broadband photodetectors.
• The liquid-phase method offers a cost-effective approach to fabricating these devices.
• This material system shows significant promise for low-cost, high-performance optoelectronic applications.