Nanoscale surface electrical properties of zinc oxide films investigated by conducting atomic force microscopy.
In this study, conducting atomic force microscopy was employed to investigate the nanoscale surface electrical properties of zinc oxide (ZnO) films prepared by pulsed laser deposition (PLD) at different substrate temperatures for use as anode materials in polymer light-emitting diodes. The results show that the surface conductivity distribution of ZnO is related to its surface structure. At substrate temperatures of 150-200 degrees C, the conducting regions may cover over 90% of the ZnO thin-film surface, thus providing the best local conductivity. Moreover, heating at substrate temperatures of above 250 degrees C can effectively make the conductivity on the ZnO surface uniform. In particular, at substrate temperatures of around 300 degrees C, the conducting regions where currents are between 1 and 2 muA may cover as much as 83% of the surface, and furthermore, the transmission ratio in the visible range is higher than 80%. This is a rather ideal production temperature for the PLD for ZnO films.
Yu
Chang-Feng
CF
Department of Applied Physics, National Chiayi University, Chiayi 600, Taiwan, Republic of China.
Chen
Sy-Hann
SH
Xie
Wen-Jia
WJ
Lin
Yung-Shao
YS
Shen
Cheng-Yu
CY
Tsai
Sheng-Jhong
SJ
Sung
Che-Wei
CW
Ay
Chyung
C
D004563:Electrochemistry / Q000379:methods*; D018625:Microscopy, Atomic Force / Q000379:methods*; D036103:Nanotechnology / Q000379:methods; D013499:Surface Properties; D013696:Temperature; D015034:Zinc Oxide / Q000737:chemistry*
D015034:Zinc Oxide