Depth profiling of organic films with X-ray photoelectron spectroscopy using C60+ and Ar+ co-sputtering.
By sputtering organic films with 10 kV, 10 nA C60+ and 0.2 kV, 300 nA Ar+ ion beams concurrently and analyzing the newly exposed surface with X-ray photoelectron spectroscopy, organic thin-film devices including an organic light-emitting diode and a polymer solar cell with an inverted structure are profiled. The chemical composition and the structure of each layer are preserved and clearly observable. Although C60+ sputtering is proven to be useful for analyzing organic thin-films, thick organic-devices cannot be profiled without the low-energy Ar+ beam co-sputtering due to the nonconstant sputtering rate of the C60+ beam. Various combinations of ion-beam doses are studied in this research. It is found that a high dosage of the Ar+ beam interferes with the C60+ ion beam, and the sputtering rate decreases with increasing the total ion current. The results suggest that the low-energy single-atom projectile can disrupt the atom deposition from the cluster ion beams and greatly extend the application of the cluster ion-sputtering. By achievement of a steady sputtering rate while minimizing the damage accumulation, this research paves the way to profiling soft matter and organic electronics.
Yu
Bang-Ying
BY
Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan, Republic of China.
Chen
Ying-Yu
YY
Wang
Wei-Ben
WB
Hsu
Mao-Feng
MF
Tsai
Shu-Ping
SP
Lin
Wei-Chun
WC
Lin
Yu-Chin
YC
Jou
Jwo-Huei
JH
Chu
Chih-Wei
CW
Shyue
Jing-Jong
JJ