Influence of MWCNT doping on performance of polymer bulk heterojunction based devices

Present study reports the influence of Multiwall carbon nanotubes (MWCNTs) doping on performance of polymer bulk heterojunction based devices. The devices have been fabricated using spin coating method on ITO substrate. FESEM confirmed not only the dispersion of MWCNT in polymer blends but also the formation of composites. The UV-Vis absorption spectra reveal that incorporation of MWCNT changes the absorption intensity and induces blue-shift. Broadening and shifting of Raman peaks were observed with the addition of MWCNT. The photoluminescence quenching observed with the doping of MWCNT indicates efficient charge transfer and diminished recombination. The influence of MWCNTs doping on the electrical properties have been studied by measuring the current-voltage characteristics of the devices. At low applied voltage, charge transport is controlled by Ohmic behavior, trap controlled space charge limited current flows at intermediate voltage followed by trap free space charge limited current at higher applied voltage.