Zinc oxide – analogue of GaN with new perspective possibilities

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.

Role of defects in one-step synthesis of Cu-doped ZnO nano-coatings by electrodeposition method with enhanced magnetic and electrical properties

“…There are different synthesis processes to develop TMdoped ZnO nanostructures such as electron beam evaporation [32], metal organic CVD (MOCVD) [33], pulsed laser deposition (PLD) [26], molecular beam epitaxy [34], and electrodeposition [35]. Among these, electrodeposition is simple with a direct approach by adding an appropriate proportion of dopant into the electrolyte solution.…”

Nonlinear Optical Properties of ZnO

“…E0 and Ed for the ordinary direction are 6.20 and 16.51 eV, respectively, whereas they are 6.08 and 16.52 eV for the extraordinary direction. 10,11 Both the ordinary and extraordinary refractive indices decreased with increasing wavelength, as shown in Figure 1(c). Therefore, the term related to the difference between the refractive indices…”

Changes in the electrical transport of ZnO under visible light

“…Due its large band gap and small spin orbit coupling, a long spin life time is expected. Therefore, ZnO is a potential candidate for room temperature spintronic applications [3,5,6]. Advantages associated with the large band gap include higher breakdown voltages, ability to sustain large electric fields, lower noise generation, and high temperature and high-power operation [2].…”