采用旋涂工艺将Pb Se三维自组装超晶格镶嵌在两层聚合物PVP中,制备了基于PVP和Pb Se三维自组装超晶格复合体系的电双稳器件,器件结构为ITO/PVP/Pb Se三维自组装超晶格/PVP/Al,研究了其电学性能和记忆效应。与参比器件ITO/PVP/Al相比,器件ITO/PVP/Pb Se三维自组装超晶格/PVP/Al的电流-电压特性呈现出非常明显的电双稳特性和非易失记忆行为,在相同的电压下同时具有两种不同的导电状态:低电导的关态和高电导的开态。当PVP与Pb Se超晶格的质量比为1∶1时,器件性能最好,其最大电流开关比为7×104,经过104s仍几乎无衰减。通过对电流-电压曲线拟合,利用不同的导电模型对器件的载流子传输机制进行了解释。结果表明,Pb Se三维自组装超晶格作为电荷陷阱,可以俘获、储存及释放电荷,对器件的电双稳性能能起决定性作用。
Electrical bistable devices utilizing three dimensional self-assembled lead selenide( PbS e) superlattices embedded between two polyvinyl pyrrolidone( PVP) layers were fabricated by using spin-coating technique. Each PbS e superlattice is a cluster with a uniform size of 50- 60 nm,which consists of hundreds of PbS e nanoparticles with an average size of 5 nm. The current-voltage characteristics for the devices with an architecture of indium-tin-oxide( ITO) / PVP / PbS e superlattices / PVP / Al exhibit electrical bistabilities and memory behaviors due to the trapping,storring,and detrapping of the PbS e superlattices. The maximum ON / OFF ratio of the current bistability for the optimal device is 7 × 10~4,and it is maintained for 1 × 10~4 s with little degradation. The electrical bistable properties and the carrier transport mechanisms of the devices are interpreted by the conduction models based on the results of fitting the current-voltage curves.