title: Pentacene disproportionation during sublimation for field-effect transistors.
abstract: At moderate temperatures in flowing gas, pentacene undergoes a disproportionation reaction to produce 6,13-dihydropentacene (DHP) and a series of polycondensed aromatic hydrocarbons, including the previously unknown peripentacene (PP). The process requires activation by heating to 320 degrees C and is possibly catalyzed by impurities such as DHP, 6,13-pentacenequinone (PQ), Al, or Fe found in the starting materials. These impurities also result in a decrease in the intrinsic field-effect mobility (FEM) of pentacene crystals. Subsequent purifications remove such impurities, thus inhibiting the formation of the disproportionation products and increasing the FEM of pentacene (2.2 cm(2)/Vs). These results clarify the importance of purification of semiconductive materials for measurements of intrinsic mobility and optimal device performance.
authors.affiliation: School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors.forename: Luke B
authors.initials: LB
authors.lastname: Roberson
authors.forename: Janusz
authors.initials: J
authors.lastname: Kowalik
authors.forename: Laren M
authors.initials: LM
authors.lastname: Tolbert
authors.forename: Christian
authors.initials: C
authors.lastname: Kloc
authors.forename: Roswitha
authors.initials: R
authors.lastname: Zeis
authors.forename: Xiaoliu
authors.initials: X
authors.lastname: Chi
authors.forename: Richard
authors.initials: R
authors.lastname: Fleming
authors.forename: Charles
authors.initials: C
authors.lastname: Wilkins