Transient photovoltaic phenomena of ITO/Si junctions

Photovoltaic decay (PVD) data were obtained from poly-Si/ITO junctions and compared to data from single crystal poly-Si/ITO junctions. Both cells featured p-type poly-Si for the upper layer. Short light pulses were pumped into the upper layer while measurements were made with an FET probe. The sampling time interval was varied from 100 nsec to several orders of magnitude slower in order to track the decay rate. Impedance data were also gathered in the form of Cole-Cole plots. The poly-Si/ITO cells exhibited a fast initial rise and rapid decay, the latter being attributed to short minority carrier lifetimes in the grain boundary at the interface. Finally, increasing the intensity and shortening the wavelength of the input reduced the open-circuit voltage and augmented the PVD rate.