Violet phosphorus transmission and photoconductance spectroscopy

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid-State Chemistry

Background:

• Violet phosphorus is a semiconducting allotrope of phosphorus.
• It possesses a layered crystalline structure with specific repeating units.
• Understanding its optoelectronic properties is key for potential applications.

Purpose of the Study:

• To investigate the optical transmission and photoconductivity of exfoliated violet phosphorus thin films.
• To identify and characterize optical transitions in violet phosphorus.
• To determine the influence of environmental conditions on its optoelectronic properties.

Main Methods:

• Synthesis of violet phosphorus via chemical vapor transport.
• Exfoliation of thin films and protection in an inert gas environment.
• Optical transmission spectroscopy and photoconductivity measurements.
• Density functional theory (DFT) calculations for bandstructure analysis.

Main Results:

• Observed peak photoconductive responsivity of 7 mA W⁻¹ at 2.8 eV.
• Identified optical transitions at van Hove singularities at 1.80 ± 0.05 eV and 1.95 ± 0.05 eV.
• DFT calculations and dipole transition analysis confirmed experimental observations.
• Significant reduction in photoconductivity and oxidation-induced blistering upon exposure to ambient conditions.

Conclusions:

• Violet phosphorus displays distinct optoelectronic characteristics.
• Environmental stability is a critical factor for its practical application.
• An inert chemical environment is essential for preserving the intrinsic optoelectronic properties of violet phosphorus.