Crystal growth behaviour in Au-ZnO nanocomposite under different annealing environments and photoswitchability

• Published in: Journal of applied physics 2012-09, Vol.112 (6)
• Main Authors: Mishra, Y. K., Chakravadhanula, V. S. K., Hrkac, V., Jebril, S., Agarwal, D. C., Mohapatra, S., Avasthi, D. K., Kienle, L., Adelung, R.
• Format: Article
• Language: English
• Subjects: ANNEALING; BEAMS; COMPOSITE MATERIALS; CRYSTAL GROWTH; DEPOSITION; ELECTRONIC STRUCTURE; EUTECTICS; GOLD; ILLUMINANCE; MELTING; MELTING POINTS; Nanomaterials; Nanorods; NANOSCIENCE AND NANOTECHNOLOGY; Nanostructure; NANOSTRUCTURES; Numerical control; SEMICONDUCTOR MATERIALS; TRANSMISSION ELECTRON MICROSCOPY; Zinc oxide; ZINC OXIDES
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4752469

The growth of gold nanoparticles and ZnO nanorods in atom beam co-sputtered Au-ZnO nanocomposite (NC) system by annealing at two different ambient conditions is demonstrated in this work. Annealing in a furnace at 600 °C (air environment) confirmed the formation of ZnO nanorods surrounded with Au nanoparticles. In-situ annealing inside a transmission electron microscope (TEM) led to the formation of gold nanocrystals with different polygonal shapes. TEM micrographs were obtained in real time at intermediate temperatures of 300 °C, 420 °C, and 600 °C under vacuum. The growth mechanisms of Au nanocrystals and ZnO nanorods are discussed in the framework of Au-Zn eutectic and Zn-melting temperatures in vacuum and air, respectively. Current-voltage responses of Au-ZnO NC nanorods in dark as well as under light illumination have been investigated and photoswitching in Au-ZnO NC system is reported. The photoswitching has been discussed in terms of Au-ZnO band-diagram.