Electrodeposition and characterization of Polyaniline to develop organic/inorganic hybrid solar cells based on Cadmium Telluride

Polyaniline thin films were prepared by an electrochemical polymerization technique on glass/FTO substrates by varying deposition potential, growth duration, pH value and concentration. Resulting materials were studied for structural, morphological, optical and electrical properties. Structural analysis shows the formation of highest crystalline emeraldine salt phase of polyaniline at a cathodic potential of 1654 mV. Optical absorption measurements have demonstrated a wide variety of energy bandgap (Eg) varying from ~0.98 to 2.32 eV for polyaniline grown by tuning the pH value during the deposition. The electrical resistivity showed an increment from 3.7 × 103 Ωcm to 39.1 × 103 Ωcm when the pH increased from 2.0 to 6.5. The diode structures of glass/FTO/CdS/CdTe/polyaniline/Au were fabricated incorporating polyaniline as a pinhole plugging layer, and assessed for their photovoltaic activities. The results show the enhancement of all the device parameters, especially in open circuit voltage and fill factors. This improvement offers a great potential for enhancing solar cell performance, and the latest results are presented in this paper.