一维轴向有机无机异质结肖特基二极管的制备及性能研究

Preparation of One-dimensional Axial Organic-inorganic Heterojunction and Its Schottky Behavior

一维有机无机杂化材料的制备一直以来是难点问题,其不同组分间协同产生的新颖性能及广泛应用前景,使其成为近年来研究热点.通过多孔氧化铝模板辅助分步电化学沉积方法,成功设计和制备了有机导电聚合物聚3,4-乙撑二氧噻吩[poly(3,4-ethylenedioxythiophene),PEDOT]和无机金属银(Ag)的分段式纳米线.使用扫描电子显微镜(SEM)和透射电子显微镜(TEM)对其形貌和结构进行了表征.采用顶端接触上电极的方式,研究了单根PEDOT纳米线和单根PEDOT-Ag异质结纳米线的伏安特性曲线.结果表明,单根异质结纳米线展现出肖特基二极管行为,正向开启电压为0.3 V,反向击穿电压为1.5 V,正向开启后电流达到微安数量级.

Preparation of one-dimensional organic-inorganic hybrid materials has always been a difficult problem,innovative performance and broad application prospects make it a hotspot in recent years.In this work,the organic conducting polymer poly（3,4-ethylenedioxythiophene）（PEDOT） and inorganic metal silver（Ag） segmented nanowires were successfully synthesized through a electrochemical deposition method in the porous anodic alumina oxide（AAO） templates.In a typical experiment,firstly a thin layer of platinum was evaporated on one side of AAO templates served as anode in a two electrode electrochemical cell,while platinum was served as cathode.PEDOT nanowires were deposited into the AAO templates in 0.1 mol/L 3,4-ethylenedioxythiophene（EDOT） and 0.02 mol/L 1-butyl-3-methylimidazolium hexafluorophosphate（[BMIM]PF6） acetonitrile solution by applying a voltage of 3 V for 20 min.Then the AAO templates contained PEDOT nanowires as a cathode was placed in another Ag＋ containing solution,Ag blocks were deposited into the AAO templates at a current of 1 mA for 20 min.So the PEDOT-Ag segmented nanowires embedded AAO templates were acquired.Finally,aligned segmented PEDOT-Ag nanowires were obtained by dissolving the templates with 6 mol/L NaOH for 6 h and repeatedly rinsed with distilled water until the pH of the solution was 7.The morphology and structure of a single PEDOT-Ag nanowire were characterized using scanning electron microscopy（SEM） and transmission electron microscopy（TEM）.The result showed that the sliver nanowire was grown epitaxially on the amorphous PEDOT nanowire.Using the top contact electrode method,we studied the I-V characteristic curves of single PEDOT nanowire and single PEDOT-Ag heterojunction nanowire.The results revealed that the single heterojunction nanowire showed a Schottky diode behavior,the forward turn-on voltage was 0.3 V,and the reverse breakdown voltage was 1.5 V.A Schottky junction formed at PEDOT/Ag interface due to the difference in work functions of two materials.To our surprise,the forward current of the Schottky diode reached microamp.Moreover,we believed that this novel nanoscale Schottky device with low turn-on voltage and huge forward current would be applied in the field of electronics,optics and catalysis.