Optical properties of single ZnO nanowires

Abstract

The optical properties of single ZnO nanowires with diameters < 200 nm are analyzed. A comparison of the photoluminescence properties of the as-grown ensemble and of an individual nanowire is given. The temperature dependence of the individual nanowire photoluminescence shows the same behavior as that of bulk material due to the wire diameter being very large compared to the exciton Bohr radius of ZnO. Furthermore, high excitation-density measurements performed on an individual nanowire are presented in which a sharp line is observed resulting from resonator effects inside the wire.

Phase Transformation Studies of Metal Oxide Nanowires

“…23,24 While the relatively strong emission from tungsten oxide nanowires relative to bulk tungsten oxide has been attributed to quantum confinement, this is not likely the explanation due to the small Bohr radius of excitons of oxide semiconductors (for example, ZnO has a Bohr radius of 1.25 nm). 25 Even though the exact values of tungsten oxide were not found, the similarity in the bandgap and the effective masses of zinc oxide with tungsten oxide can be used to suggest that there is no quantum confinement effect. It is possible that the emission is due to impurity-bound exciton emission (as in GaSb) or is due to surface state emission.…”

ZnO nanoparticles: Structural, optical and photoconductivity characteristics

“…The UV emission band is related to near band-edge (NBE) emission of the ZnO NPs, and is attributed to the recombination of free excitons by exciton-exciton collision process [13,43]. Several authors have investigated the PL properties of ZnO nanostructures [13,[43][44][45][46][47][48][49]. Generally, visible emission in ZnO consists of blue, violet, green and yellow emission peaks, which is attributed to different intrinsic defects such as oxygen vacancies (Vo), zinc vacancies (V Zn ), oxygen interstitials (Oi), zinc interstitials (Zn i ) and oxygen antisites (O Zn ).…”

Enhanced electrochemiluminescence by ZnO nanowires for taurine determination

“…The first one is related to near band-edge (NBE) emission of the ZnO nanostructure, and is attributed to the recombination of free excitons by an exciton-exciton collision process [26]. The second one is attributed to different intrinsic defects such as oxygen vacancies, zinc vacancies, oxygen interstitials, zinc interstitials and oxygen antisites [27][28][29][30][31].…”