InN films have been grown by plasma-assisted molecular beam epitaxy (PAMBE) and characterized by various technologies. It was found that the structural, optical and electrical properties can be drastically improved by raising growth temperature from 440 to 525 °C. Grainy morphology was found in the grain size was found in atomic force microscope images. The large grain size was about 360 nm for a film grown at 525 °C. These films exhibited Wurtzite structure with a c/a ratio ranging from 1.59 to 1.609. The dislocation densities estimated by X-ray diffraction techniques closely agreed with those analyzed by plan-view transmission electron microscopy. Photoluminescence (PL) studies confirmed near band-to-band transitions and the narrowest low-temperature PL peak width was found to be 24 meV at 0.666 eV. Carrier concentrations decreased from 1.44×1019 to 1.66×1018 cm-3 and Hall mobility increased from 226 to 946 cm2 V-1 s-1 as the growth temperature is progressively increased from 440 to 525 °C. Raman spectra also indicated improved crystal quality as the growth temperature was raised.
|Number of pages||6|
|Journal||Physica E: Low-Dimensional Systems and Nanostructures|
|Publication status||Published - 2009 Oct 1|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics