Plasmon phonon modes and optical resonances in n-GaN

17th Russian Youth Conference on Physics of Semiconductors and Nanostructures, Opto- and Nanoelectronics

Melentev, G.A.^1 ; Yaichnikov, D Yu^1 ; Shalygin, V.A.^1 ; Vinnichenko, M Ya^1 ; Vorobjev, L.E.^1 ; Firsov, D.A.^1 ; Riuttanen, L.^2 ; Suihkonen, S.^2

Department of Physics of Semiconductors and Nanoelectronics, Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya 29, St.Petersburg

195251, Russia^1

School of Electrical Engineering, Aalto University, Otakaari 1, Espoo

02150, Finland^2

关键词: Coupled plasmon-phonon mode;    Electron concentration;    Experimental spectra;    GaN epitaxial layers;    Mid-infrared radiation;    Radiation emissions;    Reflectivity spectra;    Wide frequency range;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/690/1/012005/pdf
DOI  :  10.1088/1742-6596/690/1/012005

来源: IOP

【 摘 要 】

We study theoretically and experimentally transverse and longitudinal electromagnetic waves in n-GaN epitaxial layers. The studies are carried out on the epitaxial layers with various doping levels. Simulation of the reflectivity and absorptivity spectra is performed in a wide frequency range. Additionally, the radiation emission spectra are simulated for various temperatures of the GaN epitaxial layer. It is shown that the resonance peculiarities of the optical spectra are located closely to the frequencies of the coupled plasmon phonon modes. Experimental studies of the reflectivity spectra have been performed in the spectral range 2-20 THz. The experimental spectra are well fitted by the simulated ones and can be used for contactless determination of the electron concentration and mobility in GaN epitaxial layers. The experimental and theoretical results of the present work provide insights for the development of GaN-based devices aimed to absorb/emit terahertz or mid infrared radiation selectively.