High-Performance Broadband Self-Driven Photodetector Based on MoS₂/Cs₂CuBr₄ Heterojunction.

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Few-layer transition metal dichalcogenides (TMDs) and perovskites are key materials for advanced optoelectronic devices.
• Developing efficient and sensitive photodetectors is crucial for various applications.

Purpose of the Study:

• To create a self-driven photodetector with high sensitivity and fast response.
• To investigate the properties of a heterojunction formed between few-layer MoS₂ and lead-free Cs₂CuBr₄ perovskite.

Main Methods:

• Fabrication of a heterojunction device using few-layer MoS₂ and Cs₂CuBr₄.
• Characterization of current-voltage (I-V) properties and photodetection performance.
• Analysis of band alignment and its effect on device behavior.

Main Results:

• The MoS₂/Cs₂CuBr₄ heterojunction exhibited rectifying behavior, attributed to a type II band alignment.
• The photodetector demonstrated broadband photodetection (400–800 nm) with high responsivity (up to 2.8 × 10⁴ A/W) and detectivity (1.6 × 10¹¹ Jones).
• The device operated effectively in self-bias mode with millisecond response times (∼32 ms rise, ∼79 ms fall).

Conclusions:

• The MoS₂/Cs₂CuBr₄ heterostructure is a promising candidate for high-performance, cost-effective photodetectors.
• The type II band alignment is critical for the observed rectifying behavior and enhanced photodetection.
• The self-driven nature and broadband sensitivity make this device suitable for diverse optoelectronic applications.