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The linear and nonlinear fluorescence spectra of 5-(9-anthryl)-3-(4-nitrophenyl)-1-phenyl-2-pyrazoline (ANPP) have been studied in different polarity solvents. The linear fluorescence spectrum of ANPP has two emission bands originating from the anthryl and pyrazoline moieties of ANPP on excitation at 355 nm. The nonlinear two-photon and three-photon fluorescence from these two moieties are observed simultaneously when ANPP is excited at 1064 nm due to the proximity of the absorption bands of these two moieties to λ/3 and λ/2 of the exciting wavelength. The similar spectrum structure indicates that the nonlinear and linear fluorescence originates from the same relaxation process.

A new compound, 5-(9-anthryl)-1,3-diphenyl-1H-pyrazol (ADPP), with an anthryl moiety as an emissive group and a diphenylpyrazoline moiety as a charge transporting group is designed and synthesized. The absorption, photoluminescence, electroluminescence, and electrochemistry are measured. Absorption of ADPP is similar to that of anthracene in the vibonic structure but shows slight redshifts because anthryl moiety twists strongly with respect to pyrazol moiety although delocalization still exists between the two moieties. Light-emitting devices fabricated with ADPP show a bright blue emission at 470 nm. The turn-on voltage is 12 V and the light emission follows the current closely, indicating an efficient charge injection and transport for both electrons and holes.

Single-layer light-emitting diodes (LEDs) are fabricated using a mixture of a blue-emitting polymer and green-emitting 9, 10-bis(phenylethynyl)anthracene as emitting layer. The blend device with these two components in the emitting layer exhibits voltage-induced evolution of the electroluminescence. But when polystyrene is also blended into the emitting layer, the EL spectra show emission bands from both ether–PPV and BPEA in proportion to concentrations of the two materials, and the spectra exhibit no change with applied voltage. This implies that doping inert polymer is helpful in suppressing voltage-induced evolution of electroluminescence in LED blends.

Influence of excimer formation on photoluminescence and electroluminescence of a novel conjugated molecule, 1-(9-anthrylethynyl)-4-chloromethyl-2,5-dimethoxybenzene (ACDB), doped in polystyrene was investigated. The monomer emission decreased and the excimer emission increased when the concentration of ACDB in the doped film was increased for photoluminescence. This resulted from the energy migration to the trapping sites of excimer. The electroluminescent device with lower concentration of ACDB in the emitting layer exhibited only the exciton emission independent of the applied voltage. The device with higher concentration exhibits exciton emission at high drive voltages but excimer emission at low drive voltages. The electric field strength dependent electroluminescent behavior with higher concentration of ACDB was explained according to the fluorescence quenching effects caused by the field-enhanced thermal dissociation of excimer. Doping polymer is helpful in suppressing the formation of excimer.

This paper outlines the band, conducting mechanism and switching effect of Cu-TCNQ. Cu-TCNQ belongs to trap controlled band conduction, it's conductivity is greatly affected by the overlap of neighboring molecular frontier orbitals whose change triggers off the switching phenomena of Cu-TCNQ.