4.1 Conclusion
In this study, we rigorously analyzed the origin which caused the distortion of performance curve, and we comprehended that the ID leakage and IDS leakage is the main contribution that cause the distortion of performance curve. Additionally, patterning the organic active layer will greatly reduce the IG leakage. Accordingly, the ID leakage will be decreased, too.
Surface treatment on gate insulator can improve the mobility of OTFTs and even reduce the threshold voltage because the order of organic material got better. However,IG leakage and IDS leakage are also increased with the improvement of the order of organic material.
Reducing the hole-injection barrier with metals have higher work function may predict in certain of material, yet the increase on ID leakage and IDS leakage is the inevitable supplementary impact.
We comprehend that interface properties can’t be predicted solely on work function and IP. Additionally, comparing to BC, the parameters (e.g., depositing rate, pressure, surface morphology of semiconductor, boiling point of metals etc.) during the depositing of metal atoms may also have influence on interface properties. But our measurement of contact resistance exactly predicted the on-current and leakage (Fig. 3-14). That is, the transfer length method may be used to predict whether the metals suit to be electrode.
4.2 Future work
As mention above, the origin which distort the electric characteristics of OTFTs are IG leakage and IDS leakage. A high quality gate insulator fabricated with low temperature processes is urgent for OTFTs to reduce power consumption and to suppress the IG leakage. However, when scaling down to the channel length, the anomalous leakage current (IDS leakage) will becomes conspicuous. In order to obtain the suppression of IDS leakage, the p/n junction-like structure of traditional MOFET may be a useful notion that used in fabrication of organic active layer.
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