Effect of Ag/Al co-doping method on optically p-type ZnO nanowires synthesized by hot-walled pulsed laser deposition
1 Electronic Materials Research Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul, 130-650, South Korea
2 Department of Semiconductor Engineering, Cheongju University, Cheongju, Chungbuk, 360-764, South Korea
3 Department of Advanced Materials Engineering, Chungbuk National University, Cheongju, 361-763, South Korea
4 Department of Materials Science and Engineering, University of Michigan-Ann Arbor, Ann Arbor, MI, 48109, USA
Nanoscale Research Letters 2012, 7:273 doi:10.1186/1556-276X-7-273Published: 30 May 2012
Silver and aluminum-co-doped zinc oxide (SAZO) nanowires (NWs) of 1, 3, and 5 at.% were grown on sapphire substrates. Low-temperature photoluminescence (PL) was studied experimentally to investigate the p-type behavior observed by the exciton bound to a neutral acceptor (A0X). The A0X was not observed in the 1 at.% SAZO NWs by low-temperature PL because 1 at.% SAZO NWs do not have a Ag-O chemical bonding as confirmed by XPS measurement. The activation energies (Ea) of the A0X were calculated to be about 18.14 and 19.77 meV for 3 and 5 at.% SAZO NWs, respectively, which are lower than the activation energy of single Ag-doped NW which is about 25 meV. These results indicate that Ag/Al co-doping method is a good candidate to make optically p-type ZnO NWs.