Impact of Humidity on the Performance and Stability of Solution-Processed Copper Oxide Transistors

We found that during spin-coating and annealing processes, the ambient humidity can have obvious impact on the characteristics of p-channel copper oxide thin-film transistors (TFTs). We studied such impact in great details along with the device operational stability. A dry deposition atmosphere (relative humidity, RH ≤ 20%) is necessary for the best device performance, including a hole mobility of 0.1 cm
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, an on/off current ratio of >104, and high operational stability (<; 2 V threshold voltage shift after 5.5 h of bias stress), attributable to residues with fewer hydroxide defects. These findings offer a clear inspiration for achieving-highly stable and reproducible p-channel oxide TFTs through a low-cost solution process.