Synthesis and characterization of naphthalene derivatives for two-component heterojunction-based ambipolar field-effect transistors complemented with copper hexadecafluorophthalocyanine (F16CuPc).

In order to develop organic semiconductor materials with good performance, herein, a series of naphthalene derivatives were designed and synthesized by a "building-blocks approach" connected through α-bond, double bond, and triple bond, respectively. Thin-film transistors were fabricated in single-component and two-component modes based on these naphthalene derivatives by combining the F16CuPc as the n-type material. The ambipolar performance was investigated by adjusting the device preparation procedure with the hole and electron mobility of up to 10-2 cm2 V-1 s-1. Furthermore, the electrical performance was also improved to 0.73 cm2 V-1 s-1 using the two-component bilayer configuration.

Solution-Processable Balanced Ambipolar Field-Effect Transistors Based on Carbonyl-Regulated Copolymers.

It is very important to develop ambipolar field effect transistors to construct complementary circuits. To obtain balanced hole- and electron-transport properties, one of the key issues is to regulate the energy levels of the frontier orbitals of the semiconductor materials by structural tailoring, so that they match well with the electrode Fermi levels. Five conjugated copolymers were synthesized and exhibited low LUMO energy levels and narrow bandgaps on account of the strong electron-withdrawing effect of the carbonyl groups. Polymer thin film transistors were prepared by using a solution method and exhibited high and balanced hole and electron mobility of up to 0.46 cm2 V-1 s-1 , which suggested that these copolymers are promising ambipolar semiconductor materials.

Diacenaphthylene-fused benzo[1,2-b:4,5-b']dithiophenes: polycyclic heteroacenes containing full-carbon five-membered aromatic rings.

We herein report on an efficient synthesis of diacenaphthylene-fused benzo[1,2-b:4,5-b']dithiophenes and demonstrate that their packing structure in the solid state depends on the substituent groups. These compounds form dimers with their radical cations in high concentration solution and exhibit good field-effect mobility.

AIE-Active Fluorene Derivatives for Solution-Processable Nondoped Blue Organic Light-Emitting Devices (OLEDs).

A series of fluorene derivatives end-capped with diphenylamino and oxadiazolyl were synthesized, and their photophysical and electrochemical properties are reported. Aggregation-induced emission (AIE) effects were observed for the materials, and bipolar characteristics of the molecules are favored with measurement of carrier mobility and calculation of molecular orbitals using density functional theory (DFT). Using the fluorene derivatives as emitting-layer, nondoped organic light-emitting devices (OLEDs) have been fabricated by spin-coating in the configuration ITO/PEDOT:PSS(35 nm)/PVK(15 nm)/PhN-OF(n)-Oxa(80 nm)/SPPO13(30 nm)/Ca(8 nm)/Al(100 nm) (n = 2-4). The best device with PhN-OF(2)-Oxa exhibits a maximum luminance of 14 747 cd/m(2), a maximum current efficiency of 4.61 cd/A, and an external quantum efficiency (EQE) of 3.09% in the blue region. Investigation of the correlation between structures and properties indicates that there is no intramolecular charge transfer (ICT) increase in these molecules with the increase of conjugation length. The device using material of the shortest conjugation length as emitting-layer gives the best electroluminescent (EL) performances in this series of oligofluorenes.

High-performance organic field-effect transistors based on single-crystalline microribbons of a two-dimensional fused heteroarene semiconductor.

A novel two-dimensional organic semiconductor material [1]benzothieno[3,2-b][1]benzothieno[2,1-b:3,4-b':6,5-b'':7,8-b''']tetra(benzothiophene) (BTBTTBT) which largely extends the scope of the π-conjugated framework of heteroarene through "H" configuration was synthesized and its thermal, optical and electrochemical properties were investigated. This 2D molecule enables the easy growth of single-crystalline microribbons by the physical vapor transport method, which were evidenced by XRD, SEM and TEM. The single-crystalline OFET devices were fabricated based on the individual BTBTTBT microribbon and the remarkable high mobility of 17.9 cm(2) V(-1) s(-1) and on/off ratios of over 10(7) could be achieved.