有机半导体在非对称金-石墨烯电极上的取向生长

Directional Growth of Organic Semiconductor on Asymmetric Gold-Graphene Electrode

为了实现在微尺度范围内有机半导体的取向生长,提出了一种基于不对称金-石墨烯电极的底接触有机薄膜晶体管器件结构。半导体前驱体溶液在不同衬底上表现出的不同接触角将打破液体/空气界面处的表面张力与表面能的总体平衡,形成马兰戈尼流并促使溶液在低润湿性的石墨烯电极表面的接触线快速后退。实验结果表明,基于这种不对称电极制备的底接触有机薄膜晶体管(OTFT)阵列的平均迁移率显著提升,达到常规对称结构器件的2倍,同时器件迁移率的相对标准差从53%下降到33%。该不对称器件结构实现了半导体薄膜在器件沟道处的取向生长,从而提高了器件迁移率与均匀性。

In order to realize the directional growth of organic semiconductors in the micro-- scale range, a bottom--contact （B--C） organic thin--film transistor device structure based on asymmetric gold--graphene electrode is proposed. Differential contact angles of the precursor so- lution on Au and graphene would break the overall balance of surface tension/surface energy （SE） at the liquid/air interface in the horizontal direction, and cause a Marangoni flow that favors receding from the less wettable surface of graphene. Experimental results indicate that the aver- age mobility of the organic thin--film transistor （OTFT） array based on this asymmetric elec- trode device structure is twice that of conventional devices of symmetric channel. While the rela- tive standard deviation of the device mobility decreased from 53% to 33%. The asymmetric de- vice structure contributes to the directional growth of the semiconductor across the channel and thereby improves the field--effect mobility and performance uniformity of the devices.