R_s

NkT/e

Ultraviolet light illumination

Off

On

Off

On

γ-irradiation

Off

On

Off

On

Off

On

Off

On

Decreasing voltage

−0.6836*

−11.245*

13.583

−2.7328*

0.3585

0.587

13.966

1.0367

Increasing voltage

−9.8453*

−2.528*

−2.5667*

6.4454

0.0248

0.1047

0.5911

1.9939