We fabricate N,N'-ditridecylperylene-3,4,9,10-tetracarboxylic diimide and pentacene heterostructure organic field effect transistors with a MoO_(3) ultrathin layer between Al source-drain electrode and active layer.By inserting the MoO_(3) layer,the injection barrier of hole carriers is lowered and the contact resistance is reduced.Thus,the performance of the device is improved.The device shows typical ambipolar transport characteristics with effective hole mobility of 4.838×10^(-3) cm^(2)/V·s and effective electron mobility of 1.909×10^(-3) cm^(2)/V·s,respectively.This result indicates that using a MoO_(3) ultrathin 1ayer is an effective way to improve the performance of ambipolar organic field effect transistors.
We have investigated the properties of C60-based organic field effect transistors（OFETs） with a tris（8- hydroxyquinoline） aluminum（Alq3） buffer layer inserted between the source/drain electrodes and the active material. The electrical characteristics of OFETs are improved with the insertion of Alq3 film.The peak field effect mobility is increased to 1.28×10-2 cm2/（V·s） and the threshold voltage is decreased to 10 V when the thickness of the Alq3 is 10 nm.The reason for the improved performance of the devices is probably due to the prevention of metal atoms diffusing into the C60 active layer and the reduction of the channel resistance in Alq3 films.
We investigated the properties of C60-based organic field-enect transistors（OFETs）（?） a pentacene passivation layer inserted between the C60 active layer and the gate dielectric.After modification of the pentacene passivation layer,the performance of the devices was considerably improved compared to C60-based OFETs with only a PMMA dielectric.The peak field-effect mobility was up to 1.01 cm2/（V·s） and the on/off ratio shifted to 104.This result indicates that using a pentacene passivation layer is an effective way to improve the performance of N-type OFETs.
Pentacene-based organic field effect transistors(OFETs) are fabricated using poly(methyl methacrylate)(PMMA) and polyimide(PI) as gate dielectrics,respectively.The fabricated OFETs exhibit reasonable device characteristics.The field-effect mobility,threshold voltage,and on/off current radio are determined to be 3.214 ×10-2 cm2 /Vs,-28 V,and 1 ×103 respectively for OFETs with PMMA as gate dielectrics,and 7.306×10-3cm2 /Vs,-21 V,and 2 ×102 for OFETs with PI.Furthermore,the dielectric properties of gate insulator layer are tested and the dipole effect at the semiconductor/dielectrics interface is also analyzed by a model of energy level diagram.
Silver nanoprisms(AgNPs) affect the performance of organic solar cells(OSCs) in different ways depending on their positions in the device. To investigate this issue, we incorporate AgNPs in different positions of OSCs and compare their performance. The power conversion efficiency(PCE) is improved by 23.60% to 3.98% when the AgNPs are incorporated in front of the active layer. On the other hand, when AgNPs are incorporated in the back of the active layer, the short-circuit current density(JSC) is improved by 17.44% to 10.84 mA/cm2. However, if AgNPs are incorporated in the active layer, both open-circuit voltage(VOC) and JSC are decreased. We discuss the position effect on the device performance, clarify the absorption shadow and exciton recombination caused by AgNPs, and finally indicate that the optimal position of plasmonic AgNPs is in front of the active layer.
We fabricate pentacene-based organic field effect transistors(OFETs),inserting a transition metal oxide(V_(2)O_(5))layer between the pentacene and Al source−drain(S/D)electrodes.The performance of the devices with V_(2)O_(5)/Al S/D electrodes is considerably improved compared to the pentacene−based OFET with only Al S/D electrodes.After the 10-nm V2O5 layer modification,the effective field-effect mobility of the devices increases from 2.7×10^(−3) cm^(2)/V⋅s to 8.93×10−1 cm^(2)/V⋅s.Owing to the change of the injection property,the effective threshold voltage(Vth)is changed from−7.5 V to−5 V and the on/off ratio shifts from 102 to 104.Moreover,the dispersion of sub−threshold current in the devices disappears.These performance improvements are ascribed to the low carrier injection barrier and the reduction of contact resistance.It is indicated that V2O5 layer modification is an effective approach to improve pentacene-based OFET performance.
