Segmented Switching TFT Channels for OLED Leakage Current Reduction

The switching TFT channel is divided into multiple segments (first channel region, second channel region, third channel region) with different semiconductor layer structures. The first and third channel regions use amorphous semiconductor with low leakage current, while the second channel region uses polycrystalline semiconductor with high mobility. This segmentation allows the device to simultaneously achieve low leakage current and high mobility by assigning different material properties to different functional regions.

Different regions of the switching TFT channel are assigned different semiconductor material qualities tailored to their specific functions. The source/drain regions and channel edges use amorphous semiconductor for low leakage, while the central channel region uses polycrystalline semiconductor for high mobility. This local differentiation of material quality optimizes both leakage current suppression and charge transport efficiency.

The channel is segmented into regions with different semiconductor properties to optimize the balance between voltage transport and leakage control. The polycrystalline second channel region ensures sufficient voltage transport capability, while the amorphous first and third channel regions suppress leakage current that would otherwise reduce the transported voltage and cause cross-talk.

The semiconductor layer structure parameters are changed along the channel length, transitioning from amorphous to polycrystalline and back to amorphous. This parameter variation optimizes the electrical characteristics by providing high mobility in the central region for voltage transport while maintaining low leakage at the boundaries to prevent cross-talk.