Oligophenyl-based organic thin film transistors

Organic thin film transistors (TFTs) have been fabricated using thermally evaporated films of the oligophenyls $p$-quaterphenyl (⁠$p$-4P), $p$-quinquephenyl (⁠$p$-5P), and $p$-sexiphenyl (⁠$p$-6P). The field-effect mobility of these TFTs ranges from $10−2 cm2/V s$ for $p$-4P to $10−1 cm2/V s$ for $p$-6P with on/off current ratio from $105$ to $106.$ These values are comparable to those achieved using the more widely studied organic semiconductors alpha-sexithienyl (α-6T) and pentacene. X-ray diffraction reveals a high degree of molecular ordering, believed to be important for obtaining high field-effect mobility in organic TFTs.