The electrical and photovoltaic properties of single junction silicon quantum dot solar cells are investigated. A prototype solar cell with an effective area of 4.7 $mm^2$ showed an open circuit voltage of 394 mV and short circuit current density of 0.062 $mA/cm^2$. A diode model with series and shunt resistances has been applied to characterize the dark current-voltage data. The photocurrent of the quantum-dot solar cell was found to be strongly dependent on the applied voltage bias, which can be understood by consideration of the conduction mechanism of the activated carriers in the quantum dot imbedded material.