Discrepancies in performance for heterojunction organic field-effect transistors with different channel lengths

Organic field-effect transistors (OFETs) with pentacene/1,1′-bis(di- 4-tolylaminophenyl) cyclohexane heterojunction structures were fabricated, and semiconductor field-effect transistor characteristics were examined for heterojunction OFETs with different channel lengths to investigate discrepancies in threshold voltage. Compared with the OFETs with short channel length, the OFETs with long channel length demonstrated a much lower threshold voltage. The decrease in threshold voltage was attributed to the reduction of charge carrier traps, and trap variation for transistors with different channel lengths was studied in detail.