Toward Next-Generation High-Speed Communication and Imaging: Solution-Processed Sb₂(S,Se)₃/CdS Heterojunction for...

Area of Science:

• Materials Science and Engineering
• Optoelectronics
• Semiconductor Physics

Background:

• Multifunctional photodetectors (PDs) are crucial for next-generation optical systems, requiring broadband responsivity, high detectivity, and extreme temperature stability.
• Existing PDs often struggle to meet all these requirements simultaneously, limiting their application in demanding environments.
• Developing cost-effective and robust PDs remains a significant challenge in optical communication and imaging.

Purpose of the Study:

• To report a novel, self-powered photodetector (PD) based on FTO/CdS/Sb₂(S,Se)₃/Au.
• To achieve multifunctional performance including broadband responsivity, high specific detectivity, ultrafast response, and extreme temperature stability.
• To demonstrate the practical applicability of the developed PD in visible light communication and high-resolution imaging.

Main Methods:

• Fabrication of a FTO/CdS/Sb₂(S,Se)₃/Au photodetector using a low-cost solution-processed method.
• Characterization of the PD's optoelectronic properties, including responsivity, specific detectivity, response/recovery times, and 3 dB bandwidth.
• Evaluation of the device's stability across a wide temperature range (10–575 K).
• Integration of the PD into a visible light communication system and as a sensing pixel for imaging.

Main Results:

• The self-powered Sb₂(S,Se)₃-based PD exhibited a responsivity of 0.6 A/W and a specific detectivity of 7.68 × 10¹² Jones at zero bias under 785 nm illumination.
• Ultrafast response and recovery times of 1.13/1.90 µs and a 3 dB bandwidth of 175 kHz were achieved.
• The unencapsulated device demonstrated remarkable stability from 10 K to 575 K.
• Successful integration into a visible light communication system and a high-resolution imaging setup validated its practical utility.

Conclusions:

• The developed solution-processed Sb₂(S,Se)₃/CdS heterojunction PD offers a promising platform for multifunctional optoelectronic applications.
• The enhanced performance is attributed to the built-in electric field and reduced trap densities at the heterojunction.
• This work presents a viable pathway for near-infrared imaging, light communication, and extreme-environment sensing applications.