Photonics with multiwall carbon nanotube arrays.

Area of Science:

• Condensed matter physics
• Materials science
• Nanophotonics

Background:

• Two-dimensional nanotube arrays exhibit unique optical properties.
• Controlling intertube spacing is crucial for tuning photonic behavior.

Purpose of the Study:

• Investigate the photonic properties of nanotube arrays for photon energies up to 40 eV.
• Explore applications in deep-ultraviolet (UV) photonic crystals and visible light absorption.
• Understand the influence of intertube spacing on photonic band gaps and optical absorption.

Main Methods:

• Computational modeling of photonic properties.
• Analysis of Bragg scattering and photonic band structures.
• Simulation of optical absorption across different spectral ranges.

Main Results:

• Small intertube spacing (20-30 nm) yields strong Bragg scattering and deep-UV photonic band gaps (25-35 eV).
• Intermediate spacing (40-100 nm) shows complex photonic structures due to anticrossing with graphite plasmon bands.
• Large spacing (>150 nm) shifts the Bragg gap to the visible range, leading to total optical absorption.

Conclusions:

• Nanotube array spacing dictates photonic properties, enabling tunable applications.
• Deep-UV photonic crystals can be achieved with specific, small intertube spacings.
• Total visible light absorption is possible with larger intertube spacings, offering potential for optical absorber devices.