An Improved Process for Fabricating High-Mobility Organic Molecular Crystal Field-Effect Transistors

In this paper we present an alternate way of making elastomer transistor stamps and high-mobility organic field-effect transistors. In particular, we have removed the need to prepare and use a silanised Si wafer for curing the stamps, and the need to handle a fragile micron-thickness polydimethylsiloxane (PDMS) film and laminate it, bubble free, against the PDMS transistor stamp. We find that despite the altered design, rougher PDMS surface, and lamination and measurement in air, we still achieve mobilities of order 10 cm(2)/Vs. Our device shows hole conduction with a threshold voltage of - 9.1 V. This corresponds to a doping concentration of 1.4 x 10(10) cm(-2), likely due to gaseous species such as oxygen adsorbed at the rubrene/PDMS interface.