p-Type ZnO Nanowire Arrays

Abstract

Well-aligned ZnO nanowire (NW) arrays with durable and reproducible p-type conductivity were synthesized on alpha-sapphire substrates by using N2O as a dopant source via vapor-liquid-solid growth. The nitrogen-doped ZnO NWs are single-crystalline and grown predominantly along the [110] direction, in contrast to the [001] direction of undoped ZnO NWs. Electrical transport measurements reveal that the nondoped ZnO NWs exhibit n-type conductivity, whereas the nitrogen-doped ZnO NWs show compensated highly resistive n-type and finally p-type conductivity upon increasing N2O ratio in the reaction atmosphere. The electrical properties of p-type ZnO NWs are stable and reproducible with a hole concentration of (1-2) x 10(18) cm(-3) and a field-effect mobility of 10-17 cm2 V(-2) s(-1). Surface adsorptions have a significant effect on the transport properties of NWs. Temperature-dependent PL spectra of N-doped ZnO NWs show acceptor-bound-exciton emission, which corroborates the p-type conductivity. The realization of p-type ZnO NWs with durable and controlled transport properties is important for fabrication of nanoscale electronic and optoelectronic devices.

One-dimensional ZnO nanostructures: Solution growth and functional properties

“…Basically, to make p-type ZnO nanowires, group-V or group-I element atoms are needed to react and then diffuse through the defects of ZnO to replace oxygen or zinc atoms in ZnO. There have been many efforts using both vapor phase [252,253] and solution phase growth approaches [254]. For example, p-type doping of ZnO nanowire arrays has been reported by post-treatment of as-grown n-type ZnO nanowires, such as using NH 3 plasma treatment [255], and thermal deposition and diffusion of As from GaAs wafers [256].…”

Comparison of Optical Properties of Ga-doped and Ag-doped ZnO Nanowire Measured at Low Temperature

“…Near the surface of the NW, many edge dislocations are found to support the dopinginduced stress. The NW growth direction is not perpendicular to the primary planes in forming the deviation from the upright ABABA stacking, implying a switch of the primary growth plane [6]. This means it is not easy to dope Ag with ZnO.…”

P-Type Phosphorus Doped ZnO Wires for Optoelectronic Applications

“…However, p-type conductivity was not stable and converted to n-type three months later. Similarly, Yuan et al [2008] reported the growth by chemical vapor deposition (CVD) of nitrogen doped ZnO wires which showed p-type FET characteristics. Lu et al [2009] reported the growth of p-type ZnO nanowires also with CVD using Zn 3 P 2 as dopant.…”