Hi, I'm running a diode on Sentaurus by Synopsys.  The structure is a simple pn junction with an imported optical generation.  I want to find the light iv curve for this structure in reverse bias.  However, when I plot it I get an unexpected result.  The current continues to increase.  I also plotted electron current and hole current.  I realized that the electron current is changing direction and increasing which it shouldn't.  It should asymptotically go to 0.  This is causing my current to keep increasing.

Does anyone know why this happens and have a possible solution?

Attached are my plots in linear and log scale.  Total Current(black) eCurrent(red) hCurrent(green)