Browsing by Author "Chen, Ying-Pin"

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Effect of deposition temperature on the channel and contact resistance of pentacene thin-film transistors
(2007)
Chen, Ying-Pin
;
Chen, Fang-Chung
;
光電工程學系
;
Department of Photonics
By varying the substrate temperature during the deposition of pentacene, the effect of temperature on the electrical performance of organic thin-film transistors, without serious disturbance of phase transition of pentacene, has been investigated. It has already understood that the device mobility goes up with temperature. The transfer line method is applied to find out the origin behind in the study. First, the channel resistance is more sensitive to the deposition temperature due to the difference size of grain. Second, among the two parts of parasitic resistance, the bulk resistance plays a more important role, and is less fluctuant to the deposition temperature. Furthermore, the contact resistance reduces with increasing deposition temperature, which is probably attributed from the difference of the molecular orientation.
Morphological study on pentacene thin-film transistors: the influence of grain boundary on the electrical properties
(2010-10-13)
Chen, Fang-Chung
;
Chen, Ying-Pin
;
Huang, Yu-Jen
;
Chien, Shang-Chieh
;
光電工程學系
We have prepared organic thin-film transistors (OTFTs) featuring pentacene molecules deposited at various substrate temperatures onto either hexamethyldisilazane (HMDS)- or poly(alpha-methylsyrene) (P alpha MS)-treated SiO(2) surfaces. As a result, we obtained different grain boundary densities in the conducting channel. Since the surface-modified devices featured similar grain boundary densities in their active layers, but displayed different electrical performances, we suspected that different trap states probably existed at the grain boundaries for the two different kinds of OTFTs. In addition, the surface morphologies of the initial layers featured grain boundaries that were rather blurred for the thin films prepared on the P alpha MS-treated substrates, whereas shallow boundaries appeared for the pentacene layers on the HMDS-treated surfaces. Therefore, we deduced that the different surface treatment processes resulted in different Schwoebel (step-edge) barriers, and hence, different morphologies. These results suggested that different trap states existed at the grain boundaries of the two types of surface-treated devices, leading to variations in the electrical performance, even though the grain boundary densities were similar.
Morphological study on pentacene thin-film transistors: the influence of grain boundary on the electrical properties
(2010-10-13)
Chen, Fang-Chung
;
Chen, Ying-Pin
;
Huang, Yu-Jen
;
Chien, Shang-Chieh
;
光電工程學系
We have prepared organic thin-film transistors (OTFTs) featuring pentacene molecules deposited at various substrate temperatures onto either hexamethyldisilazane (HMDS)- or poly(alpha-methylsyrene) (P alpha MS)-treated SiO(2) surfaces. As a result, we obtained different grain boundary densities in the conducting channel. Since the surface-modified devices featured similar grain boundary densities in their active layers, but displayed different electrical performances, we suspected that different trap states probably existed at the grain boundaries for the two different kinds of OTFTs. In addition, the surface morphologies of the initial layers featured grain boundaries that were rather blurred for the thin films prepared on the P alpha MS-treated substrates, whereas shallow boundaries appeared for the pentacene layers on the HMDS-treated surfaces. Therefore, we deduced that the different surface treatment processes resulted in different Schwoebel (step-edge) barriers, and hence, different morphologies. These results suggested that different trap states existed at the grain boundaries of the two types of surface-treated devices, leading to variations in the electrical performance, even though the grain boundary densities were similar.