Spinodal decomposition range of In x Ga 1−x N y As 1−y quaternary alloys as the result of the strain and coherency strain energies, transformations of the bonds, and a lattice mismatch between the GaAs substrate and an alloy is described. The alloys are considered in the strictly regular approximation. The strain energy is presented in the valence-force field model. The spinodal decomposition temperatures of In x Ga 1−x N y As 1−y alloys are demonstrated up to 1000 °C. It is shown that nitrogen dramatically increases the temperature of the coherent spinodal.

Copper from a solid source was diffused into undoped n-type bulk ZnO (001) single crystals at 1000 °C under a nitrogen atmosphere at different diffusion times. The Cu diffusion profiles were obtained by Secondary ion mass spectroscopy (SIMS), and the fitting reveals a diffusion case from a constant concentration source. A value for the diffusion coefficient of 2.42(±0.2) × 10⁻¹² cm²∙s⁻¹ was obtained. Electrical measurements present an increment of carrier concentration with diffusion time, but remains n-type which indicates an increase in the donor levels produced by structural defects in ZnO. Photoluminescence (PL) spectra showed an increment of green emission intensity associated with Cu incorporation.

A reliable process for the formation of nanoporous ZnO films supported on amorphous quartz and (100) silicon substrates via the processing of ZnO/Zn precursor films is reported. The process is based on the sublimation mechanism of Zn implemented in a novel ZnO/Zn precursor film to produce a nanoporous film. A scanning electron microscopy analysis of the nanoporous ZnO films’ surfaces revealed the presence of ZnO nano-features with round tips; in contrast, the nanoporous ZnO films supported on (100) Si substrates showed hexagonal nut-like nanostructures. The crystallite size of the nanoporous ZnO films decreased as the sublimation temperature was increased. X-ray photoelectron spectroscopy studies demonstrated that formations of oxygen vacancies were produced during the processing stages (as the main structural lattice defects in the ZnO nanoporous films). The analysis of the photoluminescence response confirmed that the active deep-level centers were also related to the oxygen vacancies generated during the thermal processing of the ZnO/Zn precursor films. Finally, a qualitative mechanism is proposed to explain the formation of nanoporous ZnO films on quartz and crystalline Si substrates. The results suggest that the substrates used have a strong influence on the nanoporous ZnO structures obtained with the Zn-sublimation-controlled process.