Low-Temperature Band Transport and Impact of Contact Resistance in Organic Field-Effect Transistors Based on Single-Crystal Films of Ph-BTBT-C10

Abstract

Even as technology based on solution-processable organic semiconductors advances, questions remain about their charge transport. The hallmark of $b\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}d$ $t\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}s\phantom{\rule{0}{0ex}}p\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}t$ is electron mobility that increases with decreasing temperature. Here transistors based on the polycyclic molecule Ph-BTBT-10, which crystallizes in domains that are hundreds of micrometers long, present mobility that is already high at room temperature and bandlike down to 80 K. This study demonstrates that four-probe measurements are essential to understanding intrinsic transport in these materials.