Energy relaxations of hot electrons in AlGaN/AlN/GaN heterostructures grown by MOCVD on sapphire and 6H-SiC substrates
EPJ Applied Physics
MetadataShow full item record
Please cite this item using this persistent URLhttp://hdl.handle.net/11693/21787
In this work, we investigated the hot-electron dynamics of AlGaN/GaN HEMT structures grown by MOCVD on sapphire and SiC substrates at 80 K. High-speed current-voltage measurements and Hall measurements over the temperature range 27-300 K were used to study hot-electron dynamics. At low fields, drift velocity increases linearly, but deviates from the linearity toward high electric fields. Drift velocities are deduced as approximately 6.55 × 10 6 and 6.60 × 106 cm/s at an electric field of around E ∼ 25 kV/cm for samples grown on sapphire and SiC, respectively. To obtain the electron temperature as a function of the applied electric field and power loss as a function of the electron temperature, we used the so-called mobility comparison method with power balance equations. Although their low field carrier transport properties are similar as observed from Hall measurements, hot carrier energy dissipation differs for samples grown on sapphire and SiC substrates. We found that LO-phonon lifetimes are 0.50 ps and 0.32 ps for sapphire and SiC substrates, respectively. A long hot-phonon lifetime results in large non- equilibrium hot phonons. Non-equilibrium hot phonons slow energy relaxation and increase the momentum relaxation. The effective energy relaxation times at high fields are 24 and 65 ps for samples grown on sapphire and SiC substrates, respectively. They increase as the electron temperature decreases. © EDP Sciences, 2011.
- Research Paper 7144
Showing items related by title, author, creator and subject.
Comparison of the transport properties of high quality AlGaN/AlN/GaN and AlInN/AlN/GaN two-dimensional electron gas heterostructures Tülek, R.; Ilgaz, A.; Gökden, S.; Teke, A.; Öztürk, M.K.; Kasap, M.; Öz̧elik, S.; Arslan, E.; Özbay, E. (2009)The transport properties of high mobility AlGaN/AlN/GaN and high sheet electron density AlInN/AlN/GaN two-dimensional electron gas (2DEG) heterostructures were studied. The samples were grown by metal-organic chemical vapor ...
Hakioǧlu, T.; Liberman, M.A.; Moskalenko, S.A.; Podlesny I.V. (2011)The influence of the Rashba spinorbit coupling(RSOC) on the two-dimensional (2D) electrons and holes in a strong perpendicular magnetic field leads to different results for the Landau quantization in different spin ...
Lisesivdin, S.B.; Balkan, N.; Makarovsky O.; Pataǹ, A.; Yildiz, A.; Caliskan, M.D.; Kasap, M.; Ozcelik, S.; Ozbay, E. (2009)This work describes Shubnikov-de Haas (SdH) measurements in Al0.22 Ga0.78 N/AlN/GaN/AlN heterostructures. Our experiments coupled with the analysis of the Hall data at various temperatures confirm the formation of a ...