2011 Volume 8 Issue 18 Pages 1461-1466
Pentacene based organic field-effect transistors (OFETs) with SiO2 and HfON gate insulators have been fabricated, and the effect of deposition temperature and deposition rate on the grain sizes of pentacene films was investigated. It was found that the grain sizes of pentacene films increase with increasing deposition temperature and decreasing deposition rate. Due to the increase in grain size, pentacene based OFET with HfON gate insulator shows enhanced electrical properties, such as a low subthreshold swing of 0.14V/decade and a large on/off current ratio of 1.1×104. Moreover, the hole mobility of pentacene based OFET with HfON gate insulator is 0.39cm2/Vs at an operating voltage of -2V.