Birefringence in GaN epitaxial layers and GaN microrods

作者：Trenkmann Ines^*; Uhlig Lukas; Wachs Matthias; Mounir Christian; Schwarz Ulrich T

来源：Physica Status Solidi B-Basic Solid State Physics, 2017, 254(8): 1600738.

DOI：10.1002/pssb.201600738

• birefringence
• conoscopy
• GaN
• group-III nitride semiconductors
• microrods
• thin films

Light propagating through a birefringent material undergoes a change of the state of polarization. In this article, we demonstrate the application of the non-invasive method of conoscopy to analyze the birefringence of c-plane GaN. For thick GaN bulk layers, the difference Delta n between the ordinary and extraordinary refractive index results in a modification of the state of polarization from linear to elliptical to circular and back to orthogonally linear polarization within a few degree variation of the internal angle propagation. Measurements of thin epitaxial GaN layers on c-plane sapphire show the strong influence of the sapphire substrate to the observed changes of the state of polarization.

• 出版日期2017-8