A pn junction diode and a Schottky diode have equal cross-sectional areas and have forward-bias currents of \(0.5 \mathrm{~mA}\). The reverse-saturation current of the Schottky diode is \(I_{S}=5 \times 10^{-7} \mathrm{~A}\). The difference in forward-bias voltages between the two diodes is \(0.30 \mathrm{~V}\). Determine the reverse-saturation current of the pn junction diode.