| In this study, the inkjet printability of materials important to fabricating OTFTs was researched. In order to understand the jetting evolution of inkjet printed inks, simulations were performed with a nano copper and nano particle silver ink. To predict the inkjettability of the nano copper ink, Z and Oh numbers at different temperatures were determined. The results from the simulation studies were compared to experimental results obtained using a Dimatix inkjet printer. For the semiconductor ink, the inkjet printability of two organic semiconductors, P2TDC17FT4 (poly[(3,7-diheptadecylthieno[3,2-b]thieno[2',3':4,5]thieno[2,3- d]thiophene-2,6-diyl)[2,2'-bithiophene]-5,5'-diyl] dissolved in 1,2-dichlorobenzene and P3HT (poly-3 hexylthiophene) were compared to determine the relationship between drop speed, drop volume and firing voltage, as well as the influence of drop spacing and substrate temperature on print quality. From these studies, the printability and print quality were sufficient to realize a fully inkjet printed top gate OTFT. The performance of the P2TDC17FT4, printed under ambient conditions, has important implications to the realization of low cost fully printed OTFTs.;As a post processing study, the sintering of a nano copper ink, a promising replacement for silver ink, with IPL (Intensive Pulsed Light) was researched. The relationship between ink film thickness and energy required for sintering was determined. A comparison of the energy levels required for sintering on glass and PET in relationship to ink film thickness is reported and the thermal contribution of the substrate to the processing requirements of this ink is revealed. The findings advance the current understanding of the material property needs and challenges to attaining a fully inkjet printed OTFT. |
