Pentacene films grown at various gas environment

• Main Authors: Yeh Chia-Yuan, 葉佳元
• Other Authors: Chou wei-yang
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/57429346566208272693

碩士 === 國立成功大學 === 光電科學與工程研究所 === 93 === 　　Submicron thick pentacene films deposited by molecular beam epitaxy were grown at room temperature and characterized by use of X-ray diffraction, atomic force microscopy. Pentacene-based organic thin-film transistors (OTFTs) were fabricated on a n-type silicon substrate. From the analyses of X-ray diffraction, the structure of the highly ordered pentacene films, which deposited at nitrogen environment, includes only a single “thin-film phase”. However, the pentacene film formed at high vacuum environment without injecting any gas includes two phases- a “single-crystal phase” and a “thin-film phase”. In experiments, we found that grain sizes of pentacene films were various with gas environment. Comparison with high vaccum environment, grain size of pentacene film increases 50Å while the pentacene film grows at nitrogen environment. Improved field-effect mobility, in the range 0.2 ~ 0.3 cm2/Vs, was achieved in pentacene-based OTFTs grown at nitrogen environment. The grain size of the pentacene film grown at hydrogen environment is smaller than that deposited at nitrogen environment about 100 Å, so its field-effect mobility is also decreased about 80 times.