Controlled synthesis of patterned W18O49 nanowire vertical-arrays and improved field emission performance by in situ plasma treatment

W18O49 nanowires have been intensively studied in recent years due to their good field emission (FE) performances. However, now their development has encountered difficulties, i.e., their emission uniformity is not good enough for high resolution field emission display (FED) applications. Here, we have successfully fabricated patterned, large-scale W18O49 nanowire vertical-arrays and for the first time applied an in situ plasma treatment technique to improve their field emission performance. It is found that their emission uniformity has been improved to a very high level (distribution uniformity of emission sites is higher than 96% and their brightness uniformity reaches 75.64%), while other emission properties remained unchanged compared to untreated nanowires. The bombardment of Ar plasma and the reduction of H-2 plasma may be responsible for the improvement of their FE performance. It can be concluded that this developed technique is a very effective route to enhance the emission uniformity of patterned W18O49 nanowire arrays, which may pave the way for FE emission behavior improvement of other metal oxide nanowires.