In this letter we report the use of roughly polished aluminum substrates with spin-coated polymer-smoothing layers for the fabrication of pentacene field-effect transistors. Transistors with spin-coated poly(methylrnethacrylate) gate insulator layers were fabricated and showed good performance. On the gate insulator surface, the root-mean-square roughness was found to be 0.18 nm. significantly smaller than the aluminum surface roughness, which is on the scale of tens of nanometers. Field-effect carrier mobilities extracted from the device data reached 0.75 cm 2 V -1 s -1 ; the maximum on/off current ratio was near 05 × 10 6.
Bibliographical noteFunding Information:
This work was partially supported by the NSF materials research science and engineering center program MRSEC (DMR No. 0212302). The authors gratefully acknowledge Paul V. Pesavento, Kanan P. Puntambekar, Lei Diao, Jeffrey A. Merlo, and Xiuyu Cai for experimental support.