Abstract
Thin films of cobalt tetramethoxyphenylporphyrin, CoTMPP, have been prepared via thermal evaporation method. X-ray analysis exhibits the polycrystalline and amorphous structural formation for the powder form and the film of CoTMPP, respectively. Micrographs of scanning electron microscopy reveal that the CoTMPP film is consisting of nanoparticles like spheres structure (15–28 nm) embedded in amorphous matrix. UV–Vis absorption spectroscopy of as-deposited film has been recorded and from which the Sort and Q bands are observed in a wide range of UV–Vis spectrum. Two others weak bands labeled M and N are detected in UV spectral region. In addition, the film of CoTMPP is grown on the single crystal of p-silicon (p-Si) substrate to fabricate Au/CoTMPP/p-Si/Al hybrid heterojunction solar cell. Complex impedance spectroscopy of the fabricated device is investigated from which, Nyquest spectrum is analyzed at different temperatures ranged from 300 to 380 K. The frequency dependent of the imaginary impedance and the electric modulus exhibit relaxation phenomena that attributed to the CoTMPP/p-Si and p-Si/Al interfaces, respectively. Many electrical parameters including activation energies, depletion width, life times, diffusion coefficients and mobility of the charge carriers were determined and interpreted at these interfaces.
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•Characterizations of CoTMPP films were investigated.•Au/CoTMPP/p-Si/Al heterojunction device was manufactured.•Temperature and frequency induced improvement in electrical aspects of the device.•Electronic transfer at Al/Si and CoTMPP/Si interfaces are discussed.