Toward Smart SiC Self-Powered Deep Ultraviolet Photodetectors

Area of Science:

• Materials Science
• Semiconductor Physics
• Optoelectronics

Background:

• Wide bandgap semiconductors are crucial for advanced photodetectors.
• Constructing heterojunctions enhances semiconductor device performance.
• Deep ultraviolet (DUV) photodetection requires specialized materials and structures.

Purpose of the Study:

• To construct a type-II heterojunction using lead iodide (PbI2) nanosheets on a silicon carbide (SiC) wafer.
• To investigate the DUV photoresponse and self-powered characteristics of the fabricated heterojunction photodetector.
• To evaluate the potential of SiC heterojunctions for high-performance DUV sensing.

Main Methods:

• Preparation of PbI2 nanosheets directly on a SiC wafer via a simple drop-casting method.
• Fabrication of a SiC/PbI2 type-II heterojunction photodetector.
• Characterization of the photodetector's performance, including photoresponse, dark current, and response times.

Main Results:

• The SiC/PbI2 heterojunction exhibited an enhanced DUV photoresponse compared to individual SiC or PbI2 components.
• The photodetector demonstrated excellent self-powered operation with a low dark current (1.3 × 10^-13 A) and high photocurrent-to-dark current ratio (1.5 × 10^4).
• Fast response times of 0.65 ms (rise) and 0.58 ms (decay) were achieved.

Conclusions:

• The constructed SiC type-II heterojunction effectively utilizes the built-in electric field for improved DUV photodetection.
• The device shows significant potential for omnidirectional photodetection and photocommunication applications.
• This work provides a pathway for developing high-performance, self-powered SiC-based DUV photodetectors.