Microconcave MAPbBr₃ Single Crystal for High-Performance Photodetector.

Area of Science:

• Materials Science
• Optoelectronics
• Crystallography

Background:

• Single crystals of methylammonium lead bromide (MAPbBr3) are crucial for optoelectronic applications.
• Existing methods for crystal fabrication often result in planar surfaces, limiting device performance.
• Surface morphology significantly impacts charge carrier dynamics and light interaction in photodetectors.

Purpose of the Study:

• To report a new suspension method for fabricating cubic MAPbBr3 single crystals with microconcave surfaces.
• To investigate the impact of microconcavity on crystal quality and carrier lifetime.
• To evaluate the photoelectric performance of photodetectors based on these novel MAPbBr3 crystals.

Main Methods:

• Development of a novel suspension method for cubic MAPbBr3 single crystal growth.
• Characterization of crystal crystallinity and carrier lifetime.
• Fabrication and testing of photodetectors utilizing concavity-based MAPbBr3 crystals.
• Performance evaluation under varying light intensities (3.67 μW cm⁻² and 35.4 mW cm⁻²) at 520 nm.

Main Results:

• The microconcave MAPbBr3 crystals exhibit good crystallinity and extended carrier lifetime.
• Concavity-based photodetectors demonstrate enhanced light trapping and shorter carrier pathways.
• Superior responsivity (62.9 A/W and 5.43 A/W) and EQE (1.50 × 10⁴% and 1.30 × 10³%) were achieved under low and high power irradiation, respectively.
• An ultrahigh detectivity of 6.5 × 10¹² Jones was recorded at ultralow power (3.67 μW cm⁻²), significantly outperforming planar devices.

Conclusions:

• The novel suspension method successfully produces MAPbBr3 single crystals with microconcave surfaces.
• Microconcavity enhances light trapping and carrier transport, leading to superior photodetector performance.
• This approach offers a promising pathway for developing high-performance optoelectronic devices.