Abstract
Composite nanostructures of coral reefs like p-type NiO/n-type ZnO were synthesized on fluorine-doped tin oxide glass substrates by hydrothermal growth. Structural characterization was performed by field emission scanning electron microscopy, high-resolution transmission electron microscopy, and X-ray diffraction techniques. This investigation shows that the adopted synthesis leads to high crystalline quality nanostructures. The morphological study shows that the coral reefs like nanostructures are densely packed on the ZnO nanorods. Cathodoluminescence (CL) spectra for the synthesized composite nanostructures are dominated mainly by a broad interstitial defect related luminescence centered at ~630 nm. Spatially resolved CL images reveal that the luminescence of the decorated ZnO nanostructures is enhanced by the presence of the NiO.
Highlights
ZnO has been widely used for developing optoelectronics devices due to its versatile physical characteristics including wide direct bandgap of 3.37 eV, high exciton binding energy of 60 meV, and ability to transmit light [1]
The decoration of ZnO nanorods with the NiO nanostructures was achieved by using nickel acetate and hexamethylenetetramine precursors in identical fashion as described above for
ZnO NRs were fabricated on fluorine doped tin oxide (FTO) glass substrate by the relatively cheap and simple hydrothermal growth method
Summary
ZnO has been widely used for developing optoelectronics devices due to its versatile physical characteristics including wide direct bandgap of 3.37 eV, high exciton binding energy of 60 meV, and ability to transmit light [1]. The hydrothermal growth method is considered as cheap, simple, achievable at low temperature and environmentally friendly [11,12] This method yields a material, which contains point defects contributing to defect-assisted emission under normal conditions [12]. Few studies on the fabrication of p-type NiO/n-type ZnO heterojunctions with different techniques in which the interface properties have been investigated [21]. We believe that the composite nanostructures of NiO/ZnO can pave the way for the fabrication of white LEDs due to the increased visible broad emission related to the defect states in the ZnO and defects at the interface of the heterojunction. The grown NiO/ZnO composite nanostructures have revealed an enhanced red-shift in the visible emission compared to pure. The presented composite nanostructures can be beneficial for further development of optoelectronic devices due to improved intensity of visible luminescence
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
