No abstract

Among the polycyclic aromatic hydrocarbons, although perylene is commercially available and possesses higher solubility and stability than the others, its thin-film structures and organic field-effect transistor (OFET) performances have been rarely explored. To understand its potential as an active material in OFETs, the polymorphic behaviors, packing structures, and OFET characteristics of perylene were carefully examined. The well-oriented crystal arrays of perylene prepared via droplet-pinned crystallization delivered the highest hole mobility among the reported perylene OFETs. Fluorescence microscope, electron diffraction, and lattice modeling results confirm the polymorphic behavior of perylene in the solution-processed crystal arrays and its influences on the OFET performances. The concentration-sensitive and temperature-sensitive polymorphic behavior of perylene make processing conditions crucial in the preparation of pure-phase crystal arrays. The results show the great potential of perylene as an active material in low-cost and high-performance OFETs. Moreover, the knowledge regarding the polymorphic behavior of perylene provides opportunity for the further optimization of perylene-based OFETs.

No abstract

New silicon based anodic materials in lithium ion batteries (Si-based LIBs) have been developed worldwide to overcome capacity decay during the lithiation/delithiation process. In this study, a composite of Si nanoparticles coated with 5-sulfoisophthalic acid (SPA) doped polyaniline (core/shell SiNPs@PANi/SPA) was prepared and applied as an anode material for LIB applications. The detailed structure of the core/shell SiNPs@PANi/SPA composite was characterized using high-resolution scanning electron microscopy before and after charging/discharging. The electrochemical measurements showed that the SiNPs@PANi/SPA anode exhibited a high capacity of 925 mA h g(-1) and high coulombic efficiency (99.6%) after long-term cycling (1000 cycles). Overall results indicated that the SPA doped polyaniline served as a conductive matrix to improve electrical contact and to provide an adhesive force in Si-based LIBs. Our approach opens a route for the design of efficient silicon nanocomposites for LIB applications.