In _x Al_1-xN films were deposited on Si(100) substrate using metal-organic molecular beam epitaxy. We investigated the effect of the trimethylindium/trimethylaluminum (TMIn/TMAl) flow ratios on the structural, morphological, and optical properties of In _x Al_1-xN films. Surface morphologies and microstructure of the In _x Al_1-xN films were measured by atomic force microscopy, scanning electron microscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM), respectively. Optical properties of all films were evaluated using an ultraviolet/visible/infrared (UV/Vis/IR) reflection spectrophotometer. XRD and TEM results indicated that In _x Al_1-xN films were preferentially oriented in the c-axis direction. Besides, the growth rates of In _x Al_1-xN films were measured at around 0.6 μm/h in average. Reflection spectrum shows that the optical absorption of the In _x Al_1-xN films redshifts with an increase in the In composition.

Indium nitride films grown at various growth temperatures were prepared on GaN buffer layers using self-designed plasma-assisted metal-organic molecular beam epitaxy. The influence of substrate temperature on film crystallinity, surface morphology, optical, and electrical properties was studied using x-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), UV/VIS/NIR spectrophotometer, and Hall measurement. The results show that the InN films grown on the GaN template at 500 oC are of good quality, and the full width at half maximum of InN(0002) ω-scan is around 1000 arc sec. The SEM images revealed that the average growth rate is 1.1 μm/h, which is comparable to the conventional epitaxial techniques. These results indicate that the electronic properties and crystalline quality can be significantly improved by optimizing the growth temperature.

This paper reports on high-quality InN materials prepared on a GaN template using radio-frequency metalorganic molecular beam epitaxy. We also discuss the structural and electro-optical properties of InN nanorods/films. The X-ray diffraction peaks of InN(0002) and InN(0004) were identified from their spectra, indicating that the (0001)-oriented hexagonal InN was epitaxially grown on the GaN template. Scanning electron microscopic images of the surface morphology revealed a two-dimensional growth at a rate of approximately 0.85 μm/h. Cross-sectional transmission electron microscopy images identified a sharp InN/GaN interface and a clear epitaxial orientation relationship of [0001]_InN // [0001]_GaN and ($\overline{2}110$)_InN // ($\overline{2}110$)_GaN. The optical properties of wurtzite InN nanorods were determined according to the photoluminescence, revealing a band gap of 0.77 eV.

The atomic structure of a SiGe/Si epitaxial interface grown via molecular beam epitaxy on a single crystal silicon substrate was investigated using an aberration-corrected scanning transmittance electron microscope equipped with a high-angle annular dark-field detector and an energy-dispersive spectrometer. The accuracy required for compensation of the various residual aberration coefficients to achieve sub-angstrom resolution with the electron optics system was also evaluated. It was found that the interfacial layer was composed of a silicon single crystal, connected coherently to epitaxial SiGe nanolaminates. In addition, the distance between the dumbbell structures of the Si and Ge atoms was approximately 0.136 nm at the SiGe/Si interface in the [110] orientation. The corresponding fast Fourier transform exhibited a sub-angstrom scale point resolution of 0.78 Å. Furthermore, the relative positions of the atoms in the chemical composition line scan signals could be directly interpreted from the corresponding incoherent high-angle annular dark-field image.

Wurtzite InN films were prepared on a 6H-SiC substrate by a self-designed plasma-assisted metal-organic molecular-beam epitaxy system without a buffer layer. In this article, the authors investigate the structural and optical properties of InN films grown on a 6H-SiC substrate. The crystallinity and microstructure of the thin film were further characterized by x-ray diffraction (XRD), field-emission scanning-electron microscopy, and transmission-electron microscopy. Electrical and optical properties were evaluated by Hall and photoluminescence (PL) measurements. XRD results indicate that InN film grown at 500 °C is epitaxially grown along the c-axis orientation. The two-dimensional growth mode is clearly shown in scanning-electron microscope images. Room-temperature PL spectra show that the emission peak is located at ∼0.83 eV due to the Burstein–Moss effect. In addition, the crystalline InN samples crack and peel away from the substrate at elevated growth temperature. This phenomenon may be attributed to lattice mismatch and grain coalescence while increasing the growth temperature. The narrow window of the growth temperature plays an important role in engineering the InN epitaxial growth.