Electrical characteristics of bendable a-IGZO thin-film transistors with split channels and top-gate structure

• We fabricate bendable a-IGZO TFTs with five-split channels on a plastic substrate.
• The channel width splitting effect leads to the outstanding characteristics of TFT.
• We investigate electrical properties of a-IGZO TFT as a function of bending radius.
• We categorize the operations of TFT into three regions with the bending strain.

In this study, we fabricate top-gate amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) with five split channels on a bendable plastic substrate and investigate the electrical characteristics as a function of bending curvature radius. Owing to the channel width splitting effect, our TFTs have outstanding characteristics including a high mobility of 71.8 cm2/V·s and an on/off ratio of 108. Our bending study reveals that the operation regions of our TFT are categorized into safe, transition, and definitive mechanical failure regions as the value of the bending curvature radius decreases. In the transition region, the threshold voltage is shifted from 1.0 to 2.1 V, and the mobility is decreased from 71.8 to 25.9 cm2/V·s. The electrical failure of bendable TFTs results from microcracks induced by mechanical strain.

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