Photophysical and structural aspects of perylene-doped 2-naphthol luminophors: Green emission by exciplex formation.

Several perylene (Pery)-doped 2-naphthol (2-NP) (Pery/2-NP) luminophors were prepared using conventional solid-state reaction techniques. Energy transfer in the excited state was examined using fluorescence spectroscopy and cyclic voltammetry. Fluorescence studies revealed exciplex formation by Pery in the form of structureless and broad spectra at higher concentrations with monomer quenching of 2-NP; a broad green emission was observed in the range 500-650 nm, peaking at 575 nm. Structural properties and thermal stability were analyzed using X-ray diffraction, scanning electron microscopy and TGA-differential scanning calorimetry. Highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels were observed in the range 5.56-5.61 eV and 2.79-2.81 eV, respectively with a 2.77-2.82 eV band gap. The present study reveals these to be probable candidates for hole-transporting materials suitable in optoelectronics.

Synthesis of Highly Fluorescent D-A Based p-Terphenyl Luminophors and their Thin Films for Optoelectronic Applications.

The number of anthracene-tetracene (AN-TN) doped p-terphenyl (p-TP) luminophors [(TN-AN/ p-TP) (D-A)] and thin films of polystyrene doped p-TP luminophors were prepared at different proportion by conventional technique called solid state reaction and spin coating technique respectively. Excitation energy transfer (EET) was studied by fluorimetry and cyclic voltammetry technique. The result showed that, TN-AN/ p-TP in crystalline state as well as in thin films exhibit outstanding green emission at 475-550 nm, peaking at 525 nm. Structural properties and thermal stability were studied by XRD, SEM and TGA-DSC. The HOMO and LUMO energy levels obtained by CV were in the range from 5.82-5.85 eV and 2.94-2.97 eV, respectively. The Eg calculated from the CV found 2.88 eV which are in close agreement with efficient energy transfer in prepared organoluminophors.

Synthesis of Novel Blue and Green Light Emitting 4-Nitrophenol Luminophors for Optoelectronics.

The number of anthracene (AN) and anthracene-tetracene (AN-TN) doped 4-nitrophenol (4-NP) luminophors (AN/4-NP and AN-TN/4-NP) were prepared at different proportion by conventional technique called solid state reaction. Excitation energy transfer was observed by fluorescence spectroscopy and cyclic voltammetry. 4-NP acts as an outstanding light emitting matrix. The effect of the donor emission was perceived by changing the dopant concentration; this showed that AN/4-NP and TN-AN/4-NP exhibit fluorescence emission ranging from blue to green i.e. in the range from 400 to 525 nm and 535-550 nm, respectively. Structural properties and thermal stability was studied by XRD, SEM and TGA-DSC techniques. The study reveals that the prepared materials show excellent properties which can meet the demands of optoelectronic devices as well as for light emitting devices.

Synthesis, Photophysical, Electrochemical and Thermal Study of Biphenyl Luminophors: Green Light Emitting Materials.

Novel luminophors of anthracene (AN) and tetracene (TN) doped biphenyl were prepared using Conventional Solid State reaction technique. Fluorescence spectroscopy, XRD, SEM, TGA-DSC and Cyclic Voltammetry techniques have been employed for photophysical, electrochemical and thermal study. The X-ray diffraction study revealed the formation of homogeneous biphenyl solid solutions with the added guests AN and TN. Fluorescent biphenyl absorbing short wave UV radiation and emitting at long wave UV radiation has been used as a solid matrix. From the fluorescence spectra it is seen that the added guests shifts the UV fluorescence of biphenyl emitting in green region of visible spectrum at 532 nm. SEM images of the prepared luminophors showed the crystallites of average size 140 nm which makes them suitable candidates for their use in Optoelectronic devices. HOMO and LUMO energy levels of the synthesized luminophors from electrochemical data observed in 5.50-5.64 eV and 3.09-3.13 eV with band gap 2.37-2.55 eV, respectively. TGA-DSC study revealed the thermal stability of prepared luminophors. Graphical Abstract.

Synthesis, Photophysical, Electrochemical and Thermal Investigation of Anthracene Doped 2-Naphthol Luminophors and their Thin Films for Optoelectronic Devices.

A series of novel luminophors of 2-naphthol by doping anthracene were prepared using conventional solid state reaction technique. The photophysical, electrochemical and thermal properties were studied by Fluorescence spectroscopy, XRD, SEM, TGA-DSC and by Cyclic Voltammetry techniques. The thin films were characterized by Fluorescence spectroscopy. XRD study of fine grained powders exhibited sharp peaks which specify crystallinity and homogeneity of the doped luminophors. The fluorescence spectra of doped 2-naphthol exhibited emission of anthracene at 413 nm i.e. blue emission with instantaneous fluorescence quenching of 2-NP due to excitation energy transfer (EET). Electrochemical data specify that the HOMO and LUMO energy levels of the synthesized luminophors are in the range of 5.55-5.71 eV and 3.03-3.24 eV, respectively. TGA-DSC study confirmed thermal stability of prepared luminophors. Hence, overall study proposes that these luminophors seems applicable to be used as n-type materials for Optoelectronic devices.