Jsc-Voc and Suns-Voc

Jsc Voc

A JSC VOC curve[1] is a valuable way of looking at an IV curve in the absence of series resistance. To trace a JSC VOC curve the illumination on a cell is varied and the cell JSC and VOC measured at each illumination level. The series resistance has no effect on the VOC since no current is drawn from the cell. The series resistance has no effect on JSC so long as the series resistance is less than 10 Ωcm2 since the IV curve is flat around JSC as illustrated in the series resistance page. The curve that is traced is similar to the Dark IV curve but without the effects of series resistance.

Plot Jsc@1 sun - Jsc
 
Rshunt

 
Rs

 
Rshunt

The graph on the left is a standard JV plot with the Jsc Voc point highlighted.

SunsVoc

SunsVOC measurements [2][3] are very similar to the JSC VOC measurements except that the SunsVOC uses a separate solar cell to monitor the illumination intensity rather than using the JSC of the solar cell. The monitor cell simplifies the measurement electronics since measuring cell voltage is much simpler than measuring the cell current. By using a flash lamp with a slow decay a SunsVOC can be taken very quickly and simply.

The SunsVOC measurement provides the IV curve of the diode without the effects of series resistance. Fitting to the SunsVOC curve is easier than to the dark or illuminated curves since there is no Rs.