Talwar Publishes On Optical Properties of As-Grown InN/sapphire Films

Posted on 11/17/2014 12:01:56 PM

Devki Talwar of the Physics Department published “Optical properties of plasma-assisted molecular beam epitaxy grown InN/sapphire” in the November 2014 issue of Optical Materials.

The paper is coauthored with Y. C. Liao, L. C. Chen, K. H. Chen, and Zhe Chuan Feng of the Institute of Photonics and Optoelectronics, Department of Electrical Engineering, and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei.


The optical properties of as-grown InN/sapphire films prepared by plasma assisted molecular beam epitaxy (PA-MBE) are characterized by photoluminescence (PL), Raman scattering (RS) and infrared (IR) reflectance techniques. The PL measurements have consistently exhibited lower values of InN band gaps providing clear indications of electron concentration dependent peak energy shifts and widths. The phonon modes identified by RS are found to be in good agreement with the grazing inelastic X-ray scattering measurements and ab initio lattice dynamical calculations. An effective medium theory used to analyze IR reflectance spectra of InN/sapphire films has provided reasonable estimates of free charge carrier concentrations.

Department of Physics