Properties of functionalized redox-active monolayers on thin silicon dioxide - A

2019-10-03 02:14:23

The thickness increasing oxide retention

责任者: Mathur, Guru;Gowda, Srivardhan;Li, Qiliang;Surthi, Shyam;Zhao, Qian;Misra, Veena 单位: Department of Electrical Engineering, North Carolina State University, Raleigh, NC 27695, United States 来源出处: IEEE Transactions on Nanotechnology,2005,4(2):278-283 摘要: Self-assembled monolayers of redox-active molecules were formed on varying thickness of silicon dioxide (SiO2). Cyclic voltammetry (CyV) and impedance spectroscopy (capacitance-voltage and conductance-voltage) techniques were used to characterize these structures. The charge retention properties of these molecule-oxide-silicon capacitor structures were studied by applying oxidizing voltages in two successive CyV scans without applying a reducing voltage in between the two scans. A variation of this technique, wherein a reducing voltage is applied in the second scan, was also employed. The wait time between the two scans was varied from 0 to 300 s. The number of molecules oxidized (or reduced) in the second scan increased (or decreased) with increasing wait time, which is attributed to increasing charge leakage with increasing time. The retention properties of these structures were studied and correlated to increasing oxide thickness. It was observed that the retention times increased with increasing oxide thickness if the voltage applied during the wait time was in between the oxidation and reduction peak voltages. The molecular scalability and ability to tune the retention times by varying the oxide thickness make these Si/molecular hybrid devices attractive candidates for next-generation memory applications. © 2005 IEEE. 关键词: Nanotechnology;Monolayers;Semiconducting silicon compounds;Redox reactions;Capacitors;Electric potential;Data storage equipment;Cyclic voltammetry;Spectroscopic analysis;Charge retention;Molecular memories;Redox active molecules;Impedence spectroscopy