Temperature-dependent field-effect carrier mobility in organic thin-film transistors with a gate SiO₂ dielectric modified by H₂O₂ treatment

The effect of the modification of a gate SiO₂ dielectric using an H₂O₂ solution on the temperature-dependent behavior of carrier transport for pentacene-based organic thin-film transistors (OTFTs) is studied. H₂O₂ treatment leads to the formation of Si(–OH)_x (i.e., the formation of a hydroxylated layer) on the SiO₂ surface that serves to reduce the SiO₂ capacitance and weaken the pentacene–SiO₂ interaction, thus increasing the field-effect carrier mobility (µ) in OTFTs. The temperature-dependent behavior of carrier transport is dominated by the multiple trapping model. Note that H₂O₂ treatment leads to a reduction in the activation energy. The increased value of µ is also attributed to the weakening of the interactions of the charge carriers with the SiO₂ dielectric that serves to reduce the activation energy.