Flexible, Transparent, High Mobility Amorphous In-Ga-Zn-O Thin Film Transistors Fabricated on Textile

To implement wearable textile displays (WTDs), it is essential that unique properties such as physical and chemical properties, aesthetics, and flexibility of the textile be maintained. Therefore, thin film transistors (TFTs) for WTDs should exhibit excellent electrical properties to enable 4K and 8K high resolution and high frame-rate (>120 Hz) displays while maintaining the properties of textiles. All layers of TFTs were formed by vacuum deposition and oxide-based transparent materials; amorphous In- Ga-Zn-O (a-IGZO), indium tin oxide (ITO), and Al2O3 were used. A transparent and flexible electrode with an ITO/Ag/ITO (IAI) structure was optimized and applied to the source/drain and gate. All processes were performed below 150 degrees C, and the wet -step was eliminated to prevent physical and chemical deformation of the substrate. The flexible, transparent, high mobility a-IGZO TFTs (FTH TFTs) for WTDs were fabricated on glass, polyethylene terephthalate (PET) film, and textile substrates, respectively. Their electrical performance, transparency, and flexibility were then compared. The textile-based TFTs showed transmittance of 72.98%, high mobility of 11.5 cm(2)/(V s), and an on/off ratio of 9.28 x 107 even in a low temperature process (<150 degrees C). In addition, the electrical properties of the textile-based TFTs were maintained despite testing entailing 1000 cycles of bending with a tensile strain of 0.8%. In particular, the FTH TFTs for WTDs were able to stably drive a red organic light-emitting diode on textile.

Automated summary

To implement wearable textile displays, it is important to maintain the unique properties of textiles while achieving high resolution and high frame-rate displays. This study optimized and applied transparent and flexible electrodes, as well as used vacuum deposition and oxide-based materials for thin film transistors (TFTs). Textile-based TFTs showed good electrical performance, transparency, and flexibility, even in low temperature processes. Furthermore, they demonstrated stable driving capabilities for organic light-emitting diodes on textile.