Negative Capacitance and Photocapacitance Properties of CdS Quantum Dots Based Graphene Oxide:TiO2 Nanocomposite Solar Cell

Abstract

CdS quantum dots based graphene oxide: TiO2 nanocomposite solar cells was fabricated. Graphene oxide and titanium oxide were prepared by Hummer's and sol gel methods, respectively. SEM results indicate that TiO2 is formed from the nanoparticles. CdS quantum dots were deposited on GO: TiO2 film by successive ionic layer adsorption and reaction (SILAR) method. The prepared solar cell gives a short-circuit photocurrent density (J(SC)) 0.800 mA/cm(2) and the open-circuit voltage 0.51 +/- 0.04 V under AM1.5 illumination. The photo-capacitance properties of the solar cell were analyzed by transient capacitance-time and capacitance-voltage measurements. C-V measurements indicate that the solar cell exhibited a negative capacitance behaviour. The capacitance of the solar cell is decreased with the illumination. The obtained results indicate that the solar cell can be used as a photosensor in optoelectronic applications.