Spin-coated single walled carbon nanotubes confirms p–n junction diode behavior

We demonstrate the formation of a p–n junction diode using highly mobilized p-type functionalized single-walled carbon nanotubes (SWNT’s) spin-coated on silicon substrate. The conventional methods of junction formation involve high temperature processing steps, which are compensated by using spin-coating. The fabricated diode shows an efficiency of 0.3%, fill factor 0.43, open circuit voltage 0.40mv and series resistance of 1557 O-cm2 without no high temperature processing. Hydrophobicity of the silicon oxide surface does not allow a uniform spin coating of SWNT’s, however, textured oxide surface obtained using oxygen plasma supported the formation of the diode. SWCNT’s device structure and electrical characteristics, confirming ideal diode characteristics, presented in this paper has the potential of a photovoltaic cell or solar cell diode.