Coronene is a highly symmetric organic molecule whose molecular structure resembles a fragment of graphite. We have crystallized a charge-transfer complex based on coronene and TCNQ, and present crystal structure and transport properties. The complex adopts alternate stacking between coronene and TCNQ, and the charge-transfer was estimated to be of the order of 0.3 by the structure and IR analysis of TCNQ. This degree of chargetransfer is larger than those of other hydrocarbon based charge-transfer complexes reported. We find semiconductor behavior with an optical gap of 1.55 eV and a transport gap of 0.49 eV. The Child's law mobility is estimated to be 0.3 cm 2 /Vssthis along with the small transport gap suggests this compound might be attractive for device applications.

Articles you may be interested inDielectric spectra broadening as a signature for dipole-matrix interaction. IV. Water in amino acids solutionsWe use terahertz ͑THz͒ transmission spectroscopy to obtain the frequency dependent complex dielectric constants of water, methanol, and propylene carbonate, and solutions of lithium salts in these solvents. The behavior of the pure solvents is modeled with either two ͑water͒ or three ͑methanol and propylene carbonate͒ Debye relaxations. We discuss the effects of ionic solvation on the relaxation behavior of the solvents in terms of modifications to the values of the Debye parameters of the pure solvents. In this way we obtain estimates for numbers of irrotationally bound solvent molecules, the numbers of bonds broken or formed, and the effects of ions on the higher-frequency relaxations.

We observe terahertz emission by optical rectification of an intense 1.5-eV, 50-fs pulse in single-crystal iron thin films grown by molecular beam epitaxy. The azimuthal dependence of the emission indicates the presence of a magnetic nonlinearity and a nonmagnetic surface nonlinearity.

We demonstrate the use of optical pulse-shaping technique in conjunction with difference frequency generation in a non-linear optoelectronic crystal for generating synthesized waveforms at terahertz frequencies.Spectral phase modulations, programmed using Gerchberg-Saxton algorithm and prepared in a spatial light Fourier filter, produce tailored terahertz pulses, including chirped pulses, zero-area pulses, and trains of multiple pulses for tunable narrow-band terahertz radiation up to 2.0 THz.