Electronic Materials Letters , vol. 4, no. 2, pp.85-89, June, 2008

DOI :

Protrusive Morphology of Bis(triisopropylsilylethynyl)Pentacene Nanofilms Deposited on SiO₂ Surfaces via the Vacuum Thermal Evaporation Method

Tae Kwan Kim², Hoesup Soh³, Hyunho Kim¹, Sungsoo Kim^1,*, and Jaegab Lee^1
1Kookmin University, ²GNTech Corporation, ³Hoseo University

Abstract : Highly pure 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-PEN) nanofilms were deposited on oxidized silicon wafer substrate surfaces at two different substrate temperatures (25℃ and 70℃) via the vacuum thermal evaporation (VTE) method. Atomic force and scanning electron microscope analyses showed that the TIPSPEN films (~55 nm) prepared at two different substrate temperatures commonly have a number of protrusions widespread over the films. The protrusions, which are highly likely to be crystallites, tend to be smoother and grow higher at the elevated substrate temperature (70℃), suggesting an improved crystallinity of the film. However, this study suggests that an optimum substrate temperature higher than 70℃ must be found to remove or at least minimize the protrusive morphology of TIPS-PEN semiconducting films as well as to form a perfectly polycrystalline film for an organic thin film transistor device since the morphology of a semiconductor film deeply affects the performance of a transistor.

Keyword : Triisopropylsilylethynyl-pentacene, functionalized pentacene, organic semiconductor, organic thin