Photodetector Based on Elemental Ferroelectric Black Phosphorus-like Bismuth

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Two-dimensional ferroelectric materials are key for next-generation photodetectors due to their photogalvanic effect (PGE) and light-matter interactions.
• The recent synthesis of black-phosphorus-like Bismuth (BP-Bi), an elemental ferroelectric material, opens new avenues for research.

Purpose of the Study:

• To investigate the photogalvanic effect (PGE) in monolayer (ML) BP-Bi.
• To understand the anisotropic photocurrent generation in this novel 2D ferroelectric material.

Main Methods:

• Utilized ab initio quantum transport simulations to study the PGE in ML BP-Bi.
• Analyzed photocurrent generation along different crystallographic directions (armchair and zigzag).

Main Results:

• Monolayer BP-Bi exhibits significantly higher photocurrent in the armchair (ARM) direction compared to the zigzag (ZZ) direction.
• Maximum photocurrent in the ARM direction (133 mA/W) is two orders of magnitude greater than in the ZZ direction (4.70 mA/W), despite comparable optical absorption.
• This photocurrent asymmetry is attributed to the distinct mirror inversion symmetries along the ARM and ZZ directions.

Conclusions:

• Monolayer BP-Bi demonstrates strong anisotropic photocurrent generation, driven by its ferroelectric properties.
• The findings highlight the potential of ML BP-Bi for developing high-performance, low-dimensional ferroelectric photodetectors.
• This research provides a foundation for exploring novel 2D ferroelectric materials in optoelectronic devices.