Optical Response of DyN

TL;DR

This study investigates the optical properties of polycrystalline DyN thin films, revealing its semiconducting nature, optical gap, and phonon characteristics through comprehensive spectral measurements.

Contribution

The paper provides detailed measurements of DyN's optical response, including refractive index, optical gap, and phonon modes, expanding understanding of its optical behavior.

Findings

DyN is a semiconductor with a 1.2 eV optical gap.

Doping with nitrogen vacancies introduces free carrier absorption and a Moss-Burstein shift.

Refractive index is approximately 2.0 and weakly energy-dependent.

Abstract

We report measurements of the optical response of polycrystalline DyN thin films. The frequency-dependent complex refractive index in the near IR-visible-near UV was determined by fitting reflection/transmission spectra. In conjunction with resistivity measurements these identify DyN as a semiconductor with 1.2 eV optical gap. When doped by nitrogen vacancies it shows free carrier absorption and a blue-shifted gap associated with the Moss-Burstein effect. The refractive index of 2.0+/-0.1 depends only weakly on energy. Far infrared reflectivity data show a polar phonon of frequency 280 cm-1 and dielectric strength delta epsilon= 20.