Correlation between native defects and morphological, structural and optical properties of ZnO nanostructures

Abstract

ZnO nanostructures are synthesized using chemical vapor deposition method. Well-distributed ZnO nanowires, nanogrenades and nanoislands are obtained by altering the temperature of joining the reactant gas O 2 from 550 to 570 and 600 ℃, respectively. The structural properties are derived from the X-ray diffraction patterns and Raman spectra. It is indicated that all the samples are c-oriented wurtzite ZnO. Photoluminescence spectra also indicate that ZnO nanogrenades present fewer native defects because of their lower relative intensities of visible to ultraviolet emissions (1.1) than that of ZnO nanowires (3.1) and nanoislands (1.9). The visible emission of photoluminescence spectrum is divided into green and yellow luminescence which are attributed to defects of oxygen vacancy and surface disorder, respectively. And it is found different proportions of oxygen vacancy and surface disorder of variform ZnO nanostructures.

Electrical and Optical Properties of SiO2 Thin Layers Implanted with Zn Ions

“…The increase of PL intensity via annealing can be explained by formation of ZnO phase. Namely, the weak UV band can be attributed to the near band edge emission of ZnO nanostructures attributed to the free exciton recombination which has been reported elsewhere [13,14]. The weak intensity of near band edge emission can be explained by the presence of defects in the synthesized nanoclusters.…”

“…On the other hand, the strong emission in the blue and orange spectral ranges can be related to the deep level emission resulting from the native defects in ZnO. Namely, the blue band can be originated by electron transition from the extended states of interstitial Zn (Zn i ) to the valence band [14]. The orange band can be attributed to surface disordered ZnO nanostructures and zinc vacancies and/or interstitial oxygen in ZnO [13][14][15].…”

White Electroluminescence from Aluminum Zinc Oxide Embedded in Poly(9‐vinylcarbazole)

“…Moreover, ZnO is available in large scale, chemically stable and eco‐friendly. At room temperature, the ZnO PL spectrum typically exhibits one emission peak in the ultraviolet (UV) region due to free exciton recombination and a low intensity broad emission in the visible range, associated to point defect states transitions, such as vacancies (V o and V Zn ), interstitials (O i and Zn i ) and antisites (O Zn and Zn O ) . Experimental works, theoretical studies and simulations linking defects energy level and formation energy led to some arguable hypothesis with no consensus about their origin.…”

Effect of Deposition Temperature on Self-Catalyzed ZnO Nanorods via Chemical Vapour Deposition Method

“…The usual peaks of ZnO were observed from all samples; which are the UV emission centred at 380 nm and broad visible emission (green) centred at 540 nm. It is reported by many [17,18] that the UV emission is attributed to the exciton recombination process. The UV peak intensity gradually increased as the deposition increased.…”