Through terahertz time-domain spectroscopy, negative imaginary conductivity is observed in In-rich AlInN film grown by metal-organic chemical-vapor deposition for frequencies from 0.2 to 2.0 THz. This non-Drude behavior is explained based on the electron back-scattering theory of Smith [Phys. Rev. B65, 115206 (2002)]. Comparing with binary semiconductor InN, potential fluctuations produced by composition inhomogeneity and alloy scattering of carriers make In-rich AlInN alloy easier to be subjected to non-Drude behavior in electrical performance.

Indium-rich AlInN are grown by metal-organic(MO) chemical vapor deposition using trimethylaluminum, trimethylindium, and ammonia. Under the conservation of MO influx, the effects of gas flow in the MO route on AlInN growth and Al-related parasitic reaction are investigated. With an increase in this gas flow, the suppression of Al-related parasitic reaction, i.e., enhancement in Al content incorporation and improvement of crystalline quality, is satisfactorily shown until the occurring of severe phase separation. Accordingly, Al content x in AlxIn1−xN can be tuned from x=0.02 to 0.26. The Raman spectra of those AlInN samples with phase separation are analyzed by the resonant excitation effect and two-mode behavior for A1(LO). Finally, we propose a phase diagram to interpret the phase separation and Al content evolution under the influence of gas flow

Low‐temperature (∼600 °C) MOVPE growth of GaN is investigated using a catalyst to enhance NH3 decomposition rate. As a catalyst, Ir is employed in this study. Significant differences in electrical properties between samples grown with and without catalyst are observed. The sample grown at 600 °C without catalyst shows a high resistivity (106 Ωcm) and a low carrier concentration (1011 cm‐3). The low carrier concentration is seemed to be due to the compensation by the carbon impurity known as a deep level acceptor, since the activation energy for such sample is closed to that for carbon‐doped GaN. The employment of the catalyst results in the improvement of crystalline quality of low‐temperature grown GaN. As a result of this study, we have found that the catalyst‐assisted MOVPE has significant effects on the suppression of impurity (mainly carbon) incorporation and the improvement of crystalline quality of GaN grown films. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Through terahertz time-domain spectroscopy, negative imaginary conductivity is observed in In-rich AlInN film grown by metal-organic chemical vapor deposition for frequencies from 0.2 to 2.0 THz. This non-Drude behavior is explained based on the electron back scattering theory of N. V. Smith. Comparing with binary semiconductor InN, potential fluctuations produced by composition inhomogeneity and alloy scattering of carriers make In-rich AlInN alloy easier subjected to non-Drude behavior in electrical performance.