Band engineering of ternary metal nitride system Ti1-x ZrxN for plasmonic applications

TL;DR

This study uses first-principles calculations to explore how varying Zr content in Ti1-xZrxN alloys tunes their electronic and optical properties for plasmonic applications, revealing controllable plasmonic features within the visible spectrum.

Contribution

It introduces a systematic band engineering approach to modulate the dielectric and plasmonic properties of Ti1-xZrxN alloys through composition variation.

Findings

Bulk plasma frequency can be tuned across the visible spectrum.

Lower interband transition onset in Ti-rich compounds causes higher optical losses.

ZrN exhibits higher plasmon resonance quality compared to Ti-rich alloys.

Abstract

Chemical composition is the primary factor that determines the electronic band structure and thus also influences the optical properties of plasmonic ceramics including nitrides and oxides. In this work, the optical and plasmonic properties of TiN, ZrN and their hypothetical intermediate alloys Ti1-xZrxN (x= 0, 0.25, 0.50, 0.75, and 1), are studied by using first-principles density functional theory. We demonstrate the effects of electronic band structure tuning (band engineering) on the dielectric properties by varying the concentration of metallic constituents. Our calculations reveal that bulk plasma frequency, onset of interband transitions, width of bulk plasmon resonance and cross-over frequency, can be tuned flexibly in visible spectrum region by varying the amount of Zr concentration in Ti1-xZrxN alloy system. We found that low threshold interband energy onset (~1.95 eV) leads to high losses in Ti rich compounds than that of ZrN which points to lower losses.