Nuclear Techniques ›› 2015, Vol. 38 ›› Issue (8): 80205-080205.

• LOW ENERGY ACCELERATOR, RAY AND APPLICATIONS •

### Effect on ZnO thin film photoluminescence after Ag ion implantation

LI Hao1 LIU Changlong1,2

1. 1(School of Science, Tianjin University, Tianjin 300072, China) 2(Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, Tianjin 300072, China)
• Received:2015-05-12 Revised:2015-06-15 Online:2015-08-10 Published:2015-08-13

Abstract: Background: Zinc oxide has an extensive applied prospect on photoelectric devices, like light-emitting diodes and solar cells, due to its 3.37 eV optical band gap and 60 meV excition binding energy. Recently, doping ZnO with metal elements has become a popular research topic because of the dramatic improvement on photoelectricity, piezoelectric property and conductivity. Comparing with other elements, Ag is appropriate to act as acceptor dopant element because it has a shallow acceptor level in ZnO. Therefore, many coupling systems of ZnO-Ag nanostructures have been researched. Purpose: Various methods of incorporating Ag and ZnO have been researched but it is hard to control the uniformity of doped Ag in ZnO. The quality of ZnO thin films is also one of the key factors affecting the property of samples. This paper mainly focused on how to prepare high-quality ZnO thin films by magnetron sputtering technique and how to improve the photoluminescence property of ZnO via controlling the uniformity of Ag dopant. Methods: High-quality ZnO thin films were deposited on Al2O3 substrates by magnetron sputtering technique with combination of subsequent thermal annealing. The films were then implanted with Ag ions at different energies and ?uences. We discussed the structural and photoluminescence properties of implanted ZnO thin film by means of grazing incidence X-ray diffraction (GIXRD), photoluminescence (PL), UV-vis and scanning electron microscope (SEM). Results: The PL of prepared samples showed that two bands at 380 nm and 610 nm were observed for pure ZnO films and two new peaks at 400 nm and 430 nm appeared for the implanted ZnO. Ag ion implantation strongly enhanced the excition peak of ZnO and quenched the PL peak from oxygen defect of ZnO. However, the PL bands of implanted ZnO films at 400 nm and 430 nm have been quenched after thermal annealing at nitrogen atmosphere. Conclusion: In summary, Ag nanoparticles were formed in ZnO thin films after Ag ion implantation. Thus the surface plasma resonance absorption peak from Ag nanoparticles was observed. Furthermore, the formed Ag nanoparticles quenched the oxygen defect and enhanced the excition peak of ZnO. The existence of AgZn and Agi energy levels and synthesis of Ag nanoparticles made a great improvement on the PL property of ZnO.