Enhanced Mobility in C8-BTBT Field-Effect Transistors With Iodine-Doping

Organic field-effect transistors (OFETs) are widely applied in the fields of flexible display and wearable devices. However, its mobility optimization is a major bottleneck. Here, enhanced mobility in organic dioctylbenzothienob en-zothiophene (C8-BTBT) OFETs is demonstrated with iodine doping. By optimizing the doping concentration, the carrier concentration at the metal/semiconductor interface markedly increases due to tunneling effects, generating a contact resistance (R<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\text {C}}\text {)}$ </tex-math></inline-formula> reduced by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 10^{{2}}$ </tex-math></inline-formula>, and increasing mobility from 1.4 to 10.4 cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>V<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-{1}}$ </tex-math></inline-formula>s<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-{1}}$ </tex-math></inline-formula>. This work proposes an effective method to enhance the mobility of C8-BTBT OFETs.