where τ τ F is the forward transit time of charge carriers: The first term in the charge is the charge in transit across the diode when the current I Q flows. The second term is the charge stored in the junction itself when it is viewed as a simple capacitor ; that is, as a pair of electrodes with opposite charges on them. It is the charge stored on the diode by virtue of simply having a voltage across it, regardless of any current it conducts.