Optimizing Pentacene Growth In Low-Voltage Organic Thin-Film Transistors Prepared By Dry Fabrication Techniques
We have studied the effect of pentacene purity and evaporation rate on low-voltage organic thin-film transistors (OTFTs) prepared solely by dry fabrication techniques. The maximum field-effect mobility of 0.07 cm2/Vs was achieved for the highest pentacene evaporation rate of 0.32 Å/s and four-time purified pentacene. Four-time purified pentacene also led to the lowest threshold voltage of -1.1 V and inverse subthreshold slope of ∼100 mV/decade. In addition, pentacene surface was imaged using atomic force microscopy, and the transistor channel and contact resistances for various pentacene evaporation rates were extracted and compared to field-effect mobilities.