| 초록 |
To improve the interfaces between triethylsilylethynyl anthradithiophene (TES-ADT) and SiO2 dielectrics, we introduced dimethylchlorosilane-terminated polystyrene (PS-brush) and hexamethyldisilazane (HMDS) onto the SiO2 substrates. These ultrathin layers control the surface polarity of the dielectrics as well as their capacitance and surface roughness. Millimeter-sized TES-ADT crystals were then grown on these dielectrics providing the absence of the grain boundary effects of the semiconductor. A TES-ADT OFET with a PS-brush layer was found to exhibit a high charge carrier mobility (up to 1.25 cm2/Vs) and a small subthreshold slope (0.20 V/decade), as well as negligible hysteresis. Further, long-term device stability was achieved with the TES-ADT/PS-brush interface system. The dependence of trap formation on surface polarity was investigated by using photo-excited charge-collection spectroscopy, and correlated with device stability. |
