Organic thin-film transistors are studied for their high charge mobility and low space requirement, which makes them excellent for electronics in today’s society. Research demonstrates that altering variables within the fabrication process can lead to a transistor with higher or lower charge mobility. In this investigation, 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) was applied to a silicon dioxide wafer via spin coating. Properties such as the application of a hexymethyldisilazine (HMDS) surface treatment, quench temperature, melt temperature, and quench duration, were varied throughout the process to achieve the optimal results desired.
By passing charge through the transistors via a sourcemeter, the transistor with the greatest charge mobility with an average value of 1.31 cm2/Vs between gate voltages of -25 to -75 volts was the one with a HMDS surface treatment, melted at 110℃ for one minute, and quenched at 80℃ for three minutes. This was then analyzed optically via a UV-Vis absorbance spectrum to view shifts caused by crystallization of the small molecule. These shifts showed a correlation between optimal preparation conditions and absorbance that demonstrates that localization of electrons during crystallization.
