Key factors for ultra-high on/off ratio thin-film transistors using as-grown carbon nanotube networks

Approximately 30% of as-grown carbon nanotube (CNT) networks are metallic, usually leading to a trade-off between carrier mobility and on/off ratio in CNT thin-film transistors (TFTs). Figuring out the key factors of ultra-high on/off ratio in CNT TFTs should be considerably essential for the development of large-scale electronic devices in the future. Here ultra-high on/off ratios of 10(7)-10(8) are realized for CNT TFTs with mobility of similar to 500 cm(2) V-1 s(-1). We propose that one of the key factors to achieve the high on/off ratio is a clean CNT thin film without charge traps and doping due to residual dispersant used in conventional solution processes. Moreover, on/off ratio degradation under operation voltage is significantly suppressed by decreasing the diameter of CNTs.

Automated summary

Achieving ultra-high on/off ratios in carbon nanotube thin-film transistors with high carrier mobility is crucial for the development of large-scale electronic devices. One key factor for high on/off ratio is a clean CNT thin film without charge traps and doping. Additionally, on/off ratio degradation under operation voltage can be significantly suppressed by decreasing the diameter of CNTs.