No abstract

Zinc oxide due to specific electrical, optical and acoustic properties is the important semiconductor material, which has many various applications. There is growing interest in ZnO due to its potential applicability for optoelectronic devices such as light-emitting diodes, laser diodes and detectors for UV wavelength range. ZnO properties are very close to those of widely recognized semiconductor GaN. The band gap of ZnO (3.37 eV) is close to that of GaN (3.39 eV) but ZnO exciton binding energy (60 meV) is twice larger than that of GaN (28 meV). Optically pumped UV lasing have been demonstrated at room temperature using high textured ZnO films. The excitonic gain close to 300 cm -1 was achieved. ZnO thin films are expected to have higher quantum efficiency in UV semiconductor laser than GaN. The physical properties of ZnO are considered. PEMOCVD technology was used to deposit piezoelectric and highly transparent electroconductive ZnO films. Their properties are discussed. The experiments on polycrystalline ZnO films deposited by RF magnetron sputtering at different partial pressure of oxygen are presented. AFM images were studied in tapping mode for deposited films. The investigated films were dielectric ones and had optical transparency within 65-85% at thickness in the interval 0.2-0.6 µm.

Thermal treatment of graphitic carbon nitride (g-CN) in aqueous solutions of tetraethyl ammonium hydroxide at ∼100 °C yields colloidal solutions retaining stability at a CN concentration of up to 50 g L−1 and upon dilution by a factor of 103.

We present direct measurements of the kinetics of surface relief gratings (SRGs) formation in amorphous AsxSe100−x (20≤xAs≤50) thin films. SRGs are induced in different holographic schemes of recording using near-band-gap light and their growth is further facilitated by illumination with an interference pattern and observed in real time by in situ atomic force microscopy. It is found that the kinetics of SRG formation depends upon film composition and incident light polarization. The light-stimulated vectorial surface deformations are maximized for Se-rich glasses and increase even further by additional illumination during recording.