Abstract-Terahertz absorption in GaN epitaxial layers under lateral electric field

R M Balagula1, M Ya Vinnichenko1, G A Melentev1, M D Moldavskaya1, V A Shalygin1, L E Vorobjev1,D A Firsov1, S N Danilov2 and S Suihkonen3


http://iopscience.iop.org/article/10.1088/1742-6596/741/1/012147
Variation of absorption of terahertz radiation in lateral electric field was investigated in GaN epitaxial layers. Different behaviour of the absorption modulation in electric field was observed for radiation polarized along electric field and perpendicular to it. Joint analysis of optical and transport measurements let us obtain field dependencies of mobility, electron concentration and absorption cross-section. For terahertz radiation polarized perpendicular to the electric field, results are in accordance with Drude model of free electron absorption. Another polarization demonstrates significant deviation that is yet to be studied more thoroughly.