Design,synthesis And Properties Of The Semicondutors Based On Solution-processed Phthalocyanine Complexes

Owing to the high thermal and chemical stabilities, as well as the unique optical, electrical, and properties, phthalocyanines, in particular sandwich type rare complexes, as a novel functional materials, have been expected to be widely potential application in materials science, such as in molecular electronics, molecular information storage, nonlinear optics, and material science etc. Especially using in the devices of organic field-effect transistors and chemistry sensors, it can be helpful for the design and preparation of high performance OFET devices through the combination of molecular design and interface engineering. Simultaneously, with the rapid development of industry and the demand of mankind lives, the demands of compatibility with flexible substrate and plasticity are higher and higher. It is high time to have a combination of the high-performance organic field effect transistor with flexible substrates. Our research work has been focused on the following respects:1. Air-stable ambipolarfield-effect transistor based on a solution-processed octanaphthoxysubstituted tris(phthalocyaninato) europium semiconductor with high and balanced carrier mobilitiesA new tris(phthalocyaninato) europium complex,(Pc)Eu[Pc(ONh)8]Eu[Pc(ONh)8], with a low-lying LUMO energy level(–4.00 eV) and HOMO–LUMO separation of 1.07 eV, was successfully synthesized. A simple solvent-vapor annealing approach using high boiling-point marginal solvent o-dichlorobenzene(DCB) over the quasi–Langmuir–Sh?fer(QLS) films fabricated from heteroleptic(Pc)Eu[Pc(ONh)8]Eu[Pc(ONh)8] with unsymmetrical triple-decker molecular structure and bringing peripheral slightly electron-withdrawing naphthoxy substituents led to more ordered molecular packing in the film, enabling the air-stable excellent ambipolar OFET device performance that has never been revealed for a small molecule single-component-based solution processed devices, with the high and balanced mobilities of 1.71 and 1.25 cm2 V–1 s–1, low threshold voltages of –5 and +9 V, respectively, and high on/off ratios of 106. The present result will be helpful for the design and preparation of air-stable, high performance ambipolar OFET devices with potential application in the ultra-low-cost, large-area complementary integrated circuits through the combination of molecular design and interface engineering.2. Flexible, ambipolar organic field-effect transistors based on the solution-processed films of octanaphthoxy-substituted bis(phthalocyaninato) europiumA new sandwich-type bis(phthalocyaninato) europium complex [Pc(OAr)8]Eu[Pc(OAr)8] [Pc(OAr)8 = 2,3,9,10,16,17,23,24-octanaphthoxy phthalocyanine], was synthesized and fabricated into organic field-effect transistors devices on a flexible plastic substrate by using a simple solution-based quasi–Langmuir–Sh?fer method. Ambipolar transport has been obtained in [Pc(OAr)8]Eu[Pc(OAr)8]-based thin film transistors with the carrier mobilities to 0.10 cm2 V–1 s–1 for holes and 0.01 cm2 V–1 s–1 for electrons, respectively. The energy levels of the highest occupied molecular orbital(-4.63 eV) and the lowest unoccupied molecular orbital(-3.41 eV) were obtained based on electrochemical studies of this double-decker complex. These values just simultaneously meet the energy levels required for p-type and n-type natures of organic semiconductors, suggesting the ambipolar organic semiconducting nature of this double-decker complex. This study constitutes the first attempt to fabricate low-cost, flexible ambipolar phthalocyanine-based organic field-effect transistors by using simple solution-processing methods.