| 초록 |
This report systematically describes the effects of grain structure of the underlying crystalline self-assembled monolayers (SAMs) on the pentacene films and their electrical characteristics of field-effect transistors (FETs). To control the grain structures in the crystalline SAMs, octadecyltrichlorosilane (OTS) monolayers were prepared at different temperatures: –30 °C (–30 °C OTS), –5 °C (–5 °C OTS) and 20 °C (20 °C OTS). For the –30 °C OTS case, the largest crystalline grain with the long-range orientational homogeneity of alkyl chain array was observed, compared to the cases of –5 °C and 20 °C OTSs. Furthermore, pentacene film deposited on the –30 °C OTS has superior morphological/crystalline properties, resulting in 0.5-fold lower trap state and 2.4 times higher field-effect mobility in the FET devices than those of the -5 °C OTS. This result was explained by an invigorated quasi-epitaxial growth of the pentacene film onto the –30 °C OTS having long-range homogenous alkyl chain arrays. |
