Determination of the interfacial dynamic velocity in silicon solar cells

A detailed theoretical method is presented for the determination of the interfacial dynamic velocity (IDV) Sd introduced at the edge of the space-charge region in the base of a solar cell. The method is based on a dynamic measurement at an arbitrary point on the I–V curve and exploits measurements carried out on a solar cell under illumination. A transient regime between two steady states around the operating point is investigated. The theory takes into account the carrier generation and recombination rates. The measured values of Sd are shown to depend on the cell operating conditions, and the error in the determination of Sd increases with the light intensity that is kept constant during measurements. The interfacial dynamic velocity characterizes the junction as an active interface related to the current flow through the device and appears to allow solar cell quality control since it also depends on the cell structure parameters.