Photoluminescence and field-emission characteristics of ZnO nanowires synthesized by two-step method

ZnO nanowires with excellent photoluminescence (PL) and field-emission properties were synthesized by a two-step method, and the ZnO nanowires grew along (0 0 2) direction. PL measurements showed that the ZnO nanowires have stronger ultraviolet emission properties at 376 nm and there is 3 nm blue shift after the nanowires were immersed in thiourea (TU) solution compared with those of without immersion. The immersed-ZnO nanowires show a turn-on field of 2.3 V/μm at a current density of 0.1 μA/cm and emission current density up to 1 mA/cm2 at an applied field of 6.8 V/μm, which demonstrate that the immersed-ZnO nanowires posses efficient field-emission properties in contrast with those not immersed. The ZnO nanowires may be ideal candidates for making luminescent devices and field-emission displays.