||The main purpose of this thesis was to synthesize the soluble pentacene derivatives- 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) and 6,13-bis(triethylsilylethynyl) pentacene (TES-pentacene) by Swager method. The chemical structures of TIPS-pentacene and TES-pentacene were confirmed with FTIR, 1H-NMR, and EA. The melting point of 270 ± 2 ℃was detected for TIPS-pentacene, which was close to the theoretical value of 276 ℃. The melting point of 221 ± 2 ℃was detected for TES-pentacene, which was close to the theoretical value of 210 ℃. We measured the HOMO and LUMO levels of pentacene derivatives using cyclic voltammetry and UV-visible spectroscopy. TIPS-pentacene has a HOMO level of 5.0 eV , LUMO level of 3.11 eV, and energy gap of 1.89 eV; TES-pentacene has a HOMO level of 5.1 eV, LUMO level of 3.2 eV, and energy gap of 1.9 eV.
The characteristics of thin film transistor fabricated with TIPS-pentacene and TES-pentacene, respectively, using by three solvents-chloroform, toluene, and anisole have been investigated. The optimal characteristics of OTFT fabricated TIPS-pentacene in anisole solution can achieved the mobility of 1.91 x 10-1cm2/Vs, on/off current ratio of 6.22 x 105, and threshold voltage of 2.1 V. However, the OTFT based on TES-pentacene exhibited poor performance. The XRD result showed the high crystallization of the TIPS-pentacene in anisole solution. Slower solvent evaporation encouraged by high boiling point solvents can facilitate the growth of highly ordered films and thus enhance the components of the electrical characteristics. The mobility and on/off current ratio of flexible OTFT with TIPS-pentacene in anisole solution and 10 wt% PA acted as gate dielectric layer by inkjet printing method were 6.55 × 10-2 cm2/Vs and 1.17 × 102, respectively.