衬底加热和电极修饰对提高有机场效应晶体管性能的影响

Influence of Substrate Heating and Electrodes Modifying on Performance of Organic Field-effect Transistor

通过衬底加热和氧化钼(Mo O3)修饰源漏极制备了并五苯有机场效应晶体管。研究了衬底温度和电极修饰层厚度对器件性能的影响。实验结果表明:当衬底温度为60℃、Mo O3修饰层为10 nm时,器件性能获得了显著增强,场效应迁移率由原来的3.39×10-3cm2/(V·s)提高到2.25×10-1cm2/(V·s),阈值电压由12 V降低到3 V。器件性能的改善归因于:衬底加热可以优化有源层形貌,改善载流子传输;而Mo O3修饰层显著降低了电极与有源层之间的接触势垒,提高了载流子的注入。因此,衬底加热与电极修饰对于制备高性能有机场效应晶体管是不可或缺的优化手段。

The pentacene-based organic field-effect transistor（ OFET） with a thin transition metal oxide（ Mo O3） layer between pentacene and metal（ Al） source /drain electrodes was fabricated by using substrate heating. The effects of substrate heating and Mo O3 modifying electrodes on their performance were investigated. Comparing with OFET which only has metal Al source / drain electrodes,the performance of device with 10 nm Mo O3 buffer layer is significantly enhanced under 60 ℃ substrate temperature. The field-effect mobility increased from 3. 39 × 10- 3cm2/（ V · s） to 2. 25 ×10- 1cm2/（ V·s）,meanwhile the threshold voltage decreased from 12 V to 3 V,respectively. The enhanced performances are attributed to the improvement of the high efficiency of carrier transportation and injection,which were introduced by heating substrate and inserting Mo O3 buffer layer between electrodes and active layer. Therefore,the means of substrate heating and electrodes modification are indispensable for high performance OFET.