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.
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