The TiO2/p-Si/Ag, graphene (GNR) doped TiO2/p-Si/Ag and multi-walled carbon nanotube (MWCNT) doped TiO2/p-Si/Ag heterojunction devices were fabricated by electrospinning technique at same conditions. Their structural, morphological properties, thermal analyses (TGA), and capacitance voltage characteristics were studied and compared. The undoped, GNR and MWCNT doped TiO2 structures obtained successfully according to XRD measurements. Morphological properties of the undoped, GNR and MWCNT doped TiO2 composite structures have rod or ribbon like structures. The TGA result confirmed the GNR and MWCNT doped TiO2 structures. The C-V and G-V measurements were employed for electrical characterization of the TiO2/p-Si/Ag, GNR doped TiO2/p-Si/Ag and MWCNT doped TiO2/p-Si/Ag devices for various frequencies at room temperatures. The results imparted that the capacitance and conductance behaviors of all devices are strong functions of the frequency and voltage. The electrical parameters were calculated from C−2-V plots of the heterojunction devices and compared for three devices. The transient photocapacitance plots revealed that the devices can be employed for optical communication applications.