Optical absorption studies of free (H2Pc) and rare earth (RePc) phthalocyanine doped borate glasses

Optical absorption studies offree base and rare earth incorporatedphthalocyanine doped borate glass ma­ trix are reportedfor thefirst lime. The absorptionspec­ tra recorded in the UV-VIS region show two welldefined absorption bands of phthalocyanine (Pc) molecule, namely the Soret band(B) and the Qband. The Qband always shows its characteristicsplitting in all the doped glass matrices and the intensities of these components are found to vary from one Pc to another. Some of the important optical parameters, namely optical absorp­ tion coefficient (a), molar extinction coefficient (e), absorption cross section ((5a) , oscillator strength (f), electric dipole strength (q2), absorption halfbandwidth (AA) ofthe principaloptical transitions have also been evaluated. Moreover, thespectral dependence ofrefrac­ tive index (n) and thereby the optical dielectric con­ stant (e) on wavelength yielded values of carrier concentration to effective mass ratio (N/m*) of the phthalocyanine molecule in the present glassy systems. Optical band gap (Eg) and width of the band tail (Et) are computedand their variations among the prepared samples are also discussed: Phthalocyanines are a class of organic semiconductors which have won considerable attention among scientists because of their potential applications in the pure and applied field. Their unique properties include excellent semiconductivity, photoconductivity, thermal and chemi­ cal stability and very good optical absorption in the UV­ VIS region. (I) Some of the important applications of these organic molecules are in fabrication of solar cells, electronic displays and chemical sensors and also in pho­ tocopying processes.(2-4) In addition to these applications,