P-type single-crystalline ZnO films obtained by (Na,N) dual implantation through dynamic annealing process

Single-crystalline ZnO films were grown by plasma-assisted molecular beam epitaxy technique on c-plane sapphire substrates. The films have been implanted with fixed fluence of 130 keV Na and 90 keV N ions at 460 degrees C. It is observed that dually-implanted single crystalline ZnO films exhibit p-type characteristics with hole concentration in the range of 1.24 x 10(16)-1.34 x 10(17) cm(-3), hole mobilities between 0.65 and 8.37 cm(2) V-1 s(-1), and resistivities in the range of 53.3-80.7 Omega cm by Hall-effect measurements. There are no other secondary phase appearing, with (002) ( c-plane) orientation after ion implantation as identified by the X-ray diffraction pattern. It is obtained that Na and N ions were successfully implanted and activated as acceptors measured by XPS and SIMS results. Also compared to other similar studies, lower amount of Na and N ions make p-type characteristics excellent as others deposited by traditional techniques. It is concluded that Na and N ion implantation and dynamic annealing are essential in forming p-type single-crystalline ZnO films. (C) 2017 Elsevier B.V. All rights reserved.