title: ÐÐ¿ÑÐ¸ÑÐµÑÐºÐ¸Ðµ ÑÐ²Ð¾Ð¹ÑÑÐ²Ð° Ð½Ð°Ð½Ð¾ÑÑÑÑÐºÑÑÑ AlGaN/GaN/SiC Ð² ÑÐµÑÐ°Ð³ÐµÑÑÐ¾Ð²Ð¾Ð¼ Ð´Ð¸Ð°Ð¿Ð°Ð·Ð¾Ð½Ðµ ÑÐ°ÑÑÐ¾Ñ
title: Ð²ÑÐ¿ÑÑÐºÐ½Ð°Ñ ÐºÐ²Ð°Ð»Ð¸ÑÐ¸ÐºÐ°ÑÐ¸Ð¾Ð½Ð½Ð°Ñ ÑÐ°Ð±Ð¾ÑÐ° Ð¼Ð°Ð³Ð¸ÑÑÑÐ°
titleType: Subtitle
title: Optical properties of AlGaN/GaN/SiC nanostructures in terahertz spectral range
Creators: name: ÐÐ´Ð°Ð¼Ð¾Ð², Ð Ð¾Ð¼Ð°Ð½
Publisher: name: Ð¡Ð°Ð½ÐºÑ-ÐÐµÑÐµÑÐ±ÑÑÐ³ÑÐºÐ¸Ð¹ Ð¿Ð¾Ð»Ð¸ÑÐµÑÐ½Ð¸ÑÐµÑÐºÐ¸Ð¹ ÑÐ½Ð¸Ð²ÐµÑÑÐ¸ÑÐµÑ ÐÐµÑÑÐ° ÐÐµÐ»Ð¸ÐºÐ¾Ð³Ð¾
Year: 2020
Subjects: Ð¾Ð¿ÑÐ¸ÑÐµÑÐºÐ¸Ðµ ÑÐ²Ð¾Ð¹ÑÑÐ²Ð°
Ð¿Ð¾ÐºÐ°Ð·Ð°ÑÐµÐ»Ñ Ð¿ÑÐµÐ»Ð¾Ð¼Ð»ÐµÐ½Ð¸Ñ
ÐºÐ¾ÑÑÑÐ¸ÑÐ¸ÐµÐ½Ñ Ð¿Ð¾Ð³Ð»Ð¾ÑÐµÐ½Ð¸Ñ
Ð½Ð°Ð½Ð¾ÑÑÑÑÐºÑÑÑÑ
2D ÑÐ»ÐµÐºÑÑÐ¾Ð½Ñ
TA ÑÐ¾Ð½Ð¾Ð½Ñ
AlGaN/GaN
GaN
4H-SiC
6H-SiC
optical properties
refractive index
absorption coefficient
nanostructures
2D electrons
TA phonons

description: Ð Ð°Ð±Ð¾ÑÐ° Ð¿Ð¾ÑÐ²ÑÑÐµÐ½Ð° Ð¾Ð¿ÑÐ¸ÑÐµÑÐºÐ¸Ð¼ ÑÐ²Ð¾Ð¹ÑÑÐ²Ð°Ð¼ Ð½Ð°Ð½Ð¾ÑÑÑÑÐºÑÑÑ AlGaN/GaN/SiC, Ð° ÑÐ°ÐºÐ¶Ðµ Ð¿Ð¾Ð´Ð»Ð¾Ð¶ÐµÐº Ð¸Ð· SiC. ÐÐ°Ð´Ð°ÑÐ¸, ÐºÐ¾ÑÐ¾ÑÑÐµ ÑÐµÑÐ°Ð»Ð¸ÑÑ Ð² ÑÐ¾Ð´Ðµ Ð¸ÑÑÐ»ÐµÐ´Ð¾Ð²Ð°Ð½Ð¸Ñ:
1. Ð­ÐºÑÐ¿ÐµÑÐ¸Ð¼ÐµÐ½ÑÐ°Ð»ÑÐ½Ð¾Ðµ Ð¸ÑÑÐ»ÐµÐ´Ð¾Ð²Ð°Ð½Ð¸Ðµ ÑÐ¿ÐµÐºÑÑÐ¾Ð² Ð¿ÑÐ¾Ð¿ÑÑÐºÐ°Ð½Ð¸Ñ Ð½Ð°Ð½Ð¾ÑÑÑÑÐºÑÑÑÑ Ð² ÑÐµÑÐ°Ð³ÐµÑÑÐ¾Ð²Ð¾Ð¼ Ð´Ð¸Ð°Ð¿Ð°Ð·Ð¾Ð½Ðµ Ð´Ð»Ñ ÑÐµÐ¼Ð¿ÐµÑÐ°ÑÑÑ 77 Ð¸ 300 Ð.
2. Ð¢ÐµÐ¾ÑÐµÑÐ¸ÑÐµÑÐºÐ¾Ðµ Ð¼Ð¾Ð´ÐµÐ»Ð¸ÑÐ¾Ð²Ð°Ð½Ð¸Ðµ Ð¾Ð¿ÑÐ¸ÑÐµÑÐºÐ¸Ñ ÑÐ²Ð¾Ð¹ÑÑÐ² Ð½Ð°Ð½Ð¾ÑÑÑÑÐºÑÑÑÑ Ñ Ð¿Ð¾Ð¼Ð¾ÑÑÑ Ð¼ÐµÑÐ¾Ð´Ð° Ð¼Ð°ÑÑÐ¸Ñ Ð¿ÐµÑÐµÐ½Ð¾ÑÐ°. Ð¡Ð¾Ð¿Ð¾ÑÑÐ°Ð²Ð»ÐµÐ½Ð¸Ðµ ÑÐºÑÐ¿ÐµÑÐ¸Ð¼ÐµÐ½ÑÐ° Ñ ÑÐµÐ·ÑÐ»ÑÑÐ°ÑÐ°Ð¼Ð¸ ÑÐ°ÑÑÐµÑÐ°.
3. Ð­ÐºÑÐ¿ÐµÑÐ¸Ð¼ÐµÐ½ÑÐ°Ð»ÑÐ½ÑÐµ Ð¸ÑÑÐ»ÐµÐ´Ð¾Ð²Ð°Ð½Ð¸Ñ ÑÐ¿ÐµÐºÑÑÐ¾Ð² Ð¿ÑÐ¾Ð¿ÑÑÐºÐ°Ð½Ð¸Ñ Ð¿Ð¾Ð´Ð»Ð¾Ð¶ÐµÐº Ð¸Ð· SiC. ÐÐ¿ÑÐµÐ´ÐµÐ»ÐµÐ½Ð¸Ðµ ÑÐ¿ÐµÐºÑÑÐ¾Ð² Ð¿Ð¾ÐºÐ°Ð·Ð°ÑÐµÐ»Ñ Ð¿ÑÐµÐ»Ð¾Ð¼Ð»ÐµÐ½Ð¸Ñ Ð¸ ÐºÐ¾ÑÑÑÐ¸ÑÐ¸ÐµÐ½ÑÐ° Ð¿Ð¾Ð³Ð»Ð¾ÑÐµÐ½Ð¸Ñ.
ÐÑÐ½Ð¾Ð²Ð½ÑÐµ ÑÐµÐ·ÑÐ»ÑÑÐ°ÑÑ ÑÐ°Ð±Ð¾ÑÑ: 
ÐÐ° ÑÐ¿ÐµÐºÑÑÐ°Ñ Ð¿ÑÐ¾Ð¿ÑÑÐºÐ°Ð½Ð¸Ñ Ð½Ð°Ð½Ð¾ÑÑÑÑÐºÑÑÑ Ð²ÑÑÐ²Ð»ÐµÐ½Ñ Ð¾ÑÐ¾Ð±ÐµÐ½Ð½Ð¾ÑÑÐ¸, ÑÐ²ÑÐ·Ð°Ð½Ð½ÑÐµ Ñ Ð´Ð²ÑÐ¼ÐµÑÐ½ÑÐ¼ ÑÐ»ÐµÐºÑÑÐ¾Ð½Ð½ÑÐ¼ Ð³Ð°Ð·Ð¾Ð¼. ÐÑÐ¾Ð°Ð½Ð°Ð»Ð¸Ð·Ð¸ÑÐ¾Ð²Ð°Ð½Ð° Ð¸Ñ ÑÐµÐ¼Ð¿ÐµÑÐ°ÑÑÑÐ½Ð°Ñ Ð·Ð°Ð²Ð¸ÑÐ¸Ð¼Ð¾ÑÑÑ. ÐÑÐ¾Ð°Ð½Ð°Ð»Ð¸Ð·Ð¸ÑÐ¾Ð²Ð°Ð½Ñ Ð¾ÑÐ¾Ð±ÐµÐ½Ð½Ð¾ÑÑÐ¸ Ð¿Ð¾Ð³Ð»Ð¾ÑÐµÐ½Ð¸Ñ Ð² Ð±ÑÑÐµÑÐ½Ð¾Ð¼ ÑÐ»Ð¾Ðµ Ð½Ð°Ð½Ð¾ÑÑÑÑÐºÑÑÑÑ. ÐÐ¾ÐºÐ°Ð·Ð°Ð½Ð¾, ÑÑÐ¾ Ð¿ÑÐ¾ÑÐµÑÑÑ ÑÐ°ÑÑÐµÑÐ½Ð¸Ñ ÑÐ¾Ð½Ð¾Ð½Ð¾Ð² Ð½Ð° Ð½ÐµÑÐ¾Ð²ÐµÑÑÐµÐ½ÑÑÐ²Ð°Ñ ÐºÑÐ¸ÑÑÐ°Ð»Ð»Ð¸ÑÐµÑÐºÐ¾Ð¹ ÑÐµÑÐµÑÐºÐ¸ Ð±ÑÑÐµÑÐ½Ð¾Ð³Ð¾ ÑÐ»Ð¾Ñ, Ð° ÑÐ°ÐºÐ¶Ðµ Ð½Ð° Ð°ÑÐ¾Ð¼Ð°Ñ ÑÐ³Ð»ÐµÑÐ¾Ð´Ð° Ð´Ð¾Ð¼Ð¸Ð½Ð¸ÑÑÑÑ Ð½Ð°Ð´ ÑÐ¾Ð½Ð¾Ð½-ÑÐ¾Ð½Ð¾Ð½Ð½ÑÐ¼ ÑÐ°ÑÑÐµÑÐ½Ð¸ÐµÐ¼.
ÐÐ¾Ð»ÑÑÐµÐ½Ñ ÑÐ¿ÐµÐºÑÑÑ Ð¿Ð¾ÐºÐ°Ð·Ð°ÑÐµÐ»Ñ Ð¿ÑÐµÐ»Ð¾Ð¼Ð»ÐµÐ½Ð¸Ñ Ð¸ ÐºÐ¾ÑÑÑÐ¸ÑÐ¸ÐµÐ½ÑÐ° Ð¿Ð¾Ð³Ð»Ð¾ÑÐµÐ½Ð¸Ñ Ð´Ð»Ñ Ð¿Ð¾Ð´Ð»Ð¾Ð¶ÐµÐº Ð¸Ð· 4H-SiC Ð¸ 6H-SiC. ÐÐ¾ÐºÐ°Ð·Ð°Ð½Ð¾, ÑÑÐ¾ Ð¸Ð·Ð¼ÐµÑÐµÐ½Ð¸Ñ Ð¸Ð½ÑÐµÑÑÐµÑÐµÐ½ÑÐ¸Ð¾Ð½Ð½Ð¾Ð¹ ÐºÐ°ÑÑÐ¸Ð½Ñ Ð² ÑÐ¿ÐµÐºÑÑÐµ Ð¿ÑÐ¾Ð¿ÑÑÐºÐ°Ð½Ð¸Ñ Ð²Ð±Ð»Ð¸Ð·Ð¸ Ð¢Ð-ÑÐ¾Ð½Ð¾Ð½Ð½ÑÑ ÑÐµÐ·Ð¾Ð½Ð°Ð½ÑÐ¾Ð² Ð¿Ð¾Ð·Ð²Ð¾Ð»ÑÑÑ ÑÐ°Ð·ÑÐµÑÐ¸ÑÑ Ð¿Ð¸ÐºÐ¸ Ð¿Ð¾Ð³Ð»Ð¾ÑÐµÐ½Ð¸Ñ Ñ Ð¿Ð¾Ð»ÑÑÐ¸ÑÐ¸Ð½Ð¾Ð¹ Ð² Ð½ÐµÑÐºÐ¾Ð»ÑÐºÐ¾ ÑÐ°Ð· Ð¼ÐµÐ½ÑÑÐµ, ÑÐµÐ¼ ÑÐ¿ÐµÐºÑÑÐ°Ð»ÑÐ½Ð¾Ðµ ÑÐ°Ð·ÑÐµÑÐµÐ½Ð¸Ðµ Ð¿ÑÐ¸Ð±Ð¾ÑÐ°, Ð¸ Ð¾Ð¿ÑÐµÐ´ÐµÐ»Ð¸ÑÑ Ð¸Ñ Ð¸ÑÑÐ¸Ð½Ð½ÑÑ ÑÐ¸ÑÐ¸Ð½Ñ. ÐÑÐ¸ ÑÐµÐ¼Ð¿ÐµÑÐ°ÑÑÑÐµ 300 Ð Ð²Ð¿ÐµÑÐ²ÑÐµ Ð¾Ð¿ÑÐµÐ´ÐµÐ»ÐµÐ½Ñ Ð²ÑÐµÐ¼ÐµÐ½Ð° Ð¶Ð¸Ð·Ð½Ð¸ Ð¢Ð-ÑÐ¾Ð½Ð¾Ð½Ð¾Ð² Ð² 4H- Ð¸ 6H-SiC. ÐÐ¿ÐµÑÐ²ÑÐµ Ð¸ÑÑÐ»ÐµÐ´Ð¾Ð²Ð°Ð½Ð¾ Ð¿Ð¾Ð³Ð»Ð¾ÑÐµÐ½Ð¸Ðµ Ð½Ð° Ð¢Ð-ÑÐ¾Ð½Ð¾Ð½Ð°Ñ Ð¿ÑÐ¸ ÑÐµÐ¼Ð¿ÐµÑÐ°ÑÑÑÐµ 77 Ð Ð¸ Ð¾Ð¿ÑÐµÐ´ÐµÐ»ÐµÐ½Ñ Ð¿Ð°ÑÐ°Ð¼ÐµÑÑÑ ÑÐ¾Ð½Ð¾Ð½Ð½ÑÑ ÑÐµÐ·Ð¾Ð½Ð°Ð½ÑÐ¾Ð² Ð´Ð»Ñ 4H- Ð¸ 6H-SiC.
Ð ÐµÐ·ÑÐ»ÑÑÐ°ÑÑ Ð¸ÑÑÐ»ÐµÐ´Ð¾Ð²Ð°Ð½Ð¸Ð¹ Ð¼Ð¾Ð³ÑÑ Ð±ÑÑÑ Ð¸ÑÐ¿Ð¾Ð»ÑÐ·Ð¾Ð²Ð°Ð½Ñ Ð¿ÑÐ¸ ÑÐ°Ð·ÑÐ°Ð±Ð¾ÑÐºÐµ Ð¿ÑÐ¸Ð±Ð¾ÑÐ¾Ð² ÑÐµÑÐ°Ð³ÐµÑÑÐ¾Ð²Ð¾Ð¹ ÑÐ¾ÑÐ¾Ð½Ð¸ÐºÐ¸.
description: The work is concerned with the optical properties of AlGaN/GaN/SiC nanostructures, as well as SiC substrates. Tasks that were undertaken during the research:
1. An experimental study of the transmittance spectra of the nanostructure in the terahertz-range at temperatures of 77 and 300 K.
2. Theoretical modeling of the optical properties of the nanostructure using the transfer-matrix method. Comparison of the experimental data and simulation results. 
3. An experimental investigation of the transmittance spectra of SiC substrates. Determination of the spectral dependences of refractive index and absorption coefficient.
The key results of the research are the following:
The transmittance spectra of the nanostructure revealed features related to a two-dimensional electron gas. Their temperature dependence was analyzed. Additionally the peculiarities of the buffer layer absorption were considered. It has been shown that phonon scattering processes dominate over phonon-phonon scattering on the crystal lattice imperfections in the buffer layer, as well as on carbon atoms.
The spectra of refractive index and absorption coefficient were experimentally obtained for 4H- and 6H-SiC substrates. It has been proved that precise measurements of the interference pattern in the transmission spectrum nearby TA phonon resonances enable one to resolve the absorption peaks with a half-width several times smaller than the setup resolution and to determine their original widths. At a temperature of 300 K, the lifetimes of TA phonons in 4H- and 6H-SiC were determined for the first time. The absorption by TA phonons at a temperature of 77 K was studied and the phonon resonance parameters for 4H- and 6H-SiC were determined for the first time.
The research results can be used in the development of terahertz photonics devices.