Model for the anomalous off-current of polysilicon thin-film transistors and diodes

Due to the different crystallographic orientations of the grains in polysilicon thin films, their grain boundaries exhibit a high density of crystallographic defects that are often electrically active. Applying the equations of the transitions between different defect energy levels to a simple junction theory, the qualitative and, to a certain extent, quantitative characteristic trends of the reverse current of such defected junctions can be explained. This constitutes an important modeling method of a problem that still exists in the use of polysilicon thin-film transistors for certain applications