采用湿化学刻蚀法直接在n-Si衬底上制备了硅纳米线(Si NWs),用无电镀法在制备好的硅纳米线上修饰Pt纳米粒子作为上电极以形成结构为Pt/Si NWs/n-Si/Al的肖特基二极管。研究了无电镀参数(如氯铂酸钾K2PtCl6浓度,无电镀时间)对结构为Pt/Si NWs/n-Si/Al的肖特基二极管电流-电压的影响。从所得的电流-电压特性曲线中提取了肖特基二极管的三个特征参数(理想因子、势垒高度以及串联电阻),并分析了这三个特征参数与无电镀参数的关系,从而确定了一个制备结构为Pt/Si NWs/n-Si/Al肖特基二极管的理想条件。研究还发现所制备的肖特基二极管理想因子大于1,势垒高度~0.67eV,与金属铂(Pt)的功函数无关,这些特性可以用巴丁模型来解释。
Silicon nanowires(SiNWs) were fabricated directly on n-Si substrate by wet chemical etching at room temperature under 1atm.And the novel tridimensional Pt/SiNWs/n-Si/Al Schottky diode structures were fabricated through modifying SiNWs with platinum(Pt) nanoparticles by the electroless plating as the top electrodes.The influences of the electroless plating parameters(K2PtCl6 concentration,processing time) on current-voltage characteristics of the Pt/SiNWs/n-Si/Al Schottky diode structures were investigated,respectively.The electrical parameters(ideality factor,barrier height and series resistance) as a function of electroless plating parameters were calculated from the obtained I-V characteristics.The optimal parameters for forming the Pt/SiNWs/n-Si/Al Schottky diode structures are obtained: 10mM K2PtCl6 solutions and 10min electroless plating time.The diode ideality factors are greater than unity.The barrier height is about 0.67eV and independent of Pt work function.Those electrical characteristics of the Pt/SiNWs/n-Si/Al Schottky diode structures can be interpreted on the basis of Bardeen model.