First-Principle Study of the Optical Properties of Dilute-P GaN1-xPx Alloys

Damir Borovac; Chee-Keong Tan; Nelson Tansu

doi:10.1038/s41598-018-24384-1

First-Principle Study of the Optical Properties of Dilute-P GaN_1-xP_x Alloys

Sci Rep. 2018 Apr 16;8(1):6025. doi: 10.1038/s41598-018-24384-1.

Authors

Damir Borovac¹, Chee-Keong Tan², Nelson Tansu³

Affiliations

¹ Center for Photonics and Nanoelectronics, Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA, 18015, USA. dab315@lehigh.edu.
² Department of Electrical and Computer Engineering, Clarkson University, Potsdam, NY, 13699, USA.
³ Center for Photonics and Nanoelectronics, Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA, 18015, USA. tansu@lehigh.edu.

Abstract

An investigation on the optical properties of dilute-P GaN_1-xP_x alloys by First-Principle Density Functional Theory (DFT) methods is presented, for phosphorus (P) content varying from 0% up to 12.5%. Findings on the imaginary and real part of the dielectric function are analyzed and the results are compared with previously reported theoretical works on GaN. The complex refractive index, normal-incidence reflectivity and birefringence are presented and a difference in the refractive index in the visible regime between GaN and GaNP alloys of ~0.3 can be engineered by adding minute amounts of phosphorus, indicating strong potential for refractive index tunability. The optical properties of the GaN_1-xP_x alloys indicate their strong potential for implementation in various III-nitride-based photonic waveguide applications and Distributed Bragg Reflectors (DBR).