Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8036711 | Thin Solid Films | 2013 | 4 Pages |
Abstract
InN thin films have been grown using a pressurized-reactor metalorganic vapor phase epitaxy system at 500-700 °C under the pressure of 2.1 Ã 105 Pa. Photoluminescence (PL), optical reflectance and transmission measurements were performed at room temperature. We found that optical properties of these as-grown films strongly depend on the growth temperature. By analyzing the reflectance spectra, it is found that the calculated carrier concentrations of the films increased with decreasing growth temperature. Room-temperature photoluminescence spectra show that the films grown at temperatures higher than 575 °C have strong emission peaks at 0.68-0.75 eV, while those grown at temperatures lower than and equal to 575 °C have negligible emission. The quenching of the emission is attributed to the existences of cubic InN and a high-density of nonradiative recombination centers in the films grown at low growth temperature region. Especially for the case of high temperature growth, the growth temperature dependence of the absorption-edge energy shows a similar tendency with that of the PL peak energy, both blue-shifted with decreasing the growth temperature possibly due to the well-known Burstein-Moss effects. From these results, an optimum growth temperature of 675 °C in the pressurized growth could be obtained.
Related Topics
Physical Sciences and Engineering
Materials Science
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Authors
Yuantao Zhang, Takeshi Kimura, Kiattiwut Prasertusk, Takuya Iwabuchi, Suresh Kumar, Yuhuai Liu, Ryuji Katayama, Takashi Matsuoka,