pH-gated single-electron tunneling in chemically modified gold nanoclusters
pH-gated single-electron tunneling in chemically modified gold nanoclusters
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DOI：
10.1021/ja981262s
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发表时间：
1998-08-05
影响因子：
15
通讯作者：
Feldheim, DL
中科院分区：
文献类型：
--
作者：
Brousseau, LC;Zhao, Q;Feldheim, DL
当通过单个电子对岛充电所需的能量e2/CT（e是电子电荷，CT是总岛电容）相对于由热能（kT）提供的能量大时，在金属岛中发生电子一个接一个的相关转移。[1]尽管自20世纪60年代初以来，人们一直在研究单电子隧穿（SET），但由于采用电子衍射法制备的器件尺寸相对较大，因此需要极低的温度（通常低于开尔文）来观察SET行为。2最近合成配体稳定的金属（Au，Ag，Pt）3和半导体（CdS，CdSe）纳米团簇的方法，直径< 10 nm，使隧道结的电容< 10-18 F的电子表征;事实上，SET现在已经在室温下在几个纳米级系统中观察到。5这些实验重新激发了人们对使用单电子器件作为数据存储元件的热情，其中信息位由单电子表示。将单电子器件纳入纳米级电子电路的一个重大挑战是SET电流对可能存在于纳米颗粒上或附近的杂质的敏感性。1杂质在SET电流-电压（i-V）曲线中引入偏移，使得任何两个SET器件都不可能是电子等效的。用于克服电流偏移的一种所提出的方法是使用栅极电极来“复位”器件。我们的小组一直在考虑采用粒子帽配体作为“化学门”来操纵SET电流的可能性。发展对封端配体化学如何影响纳米团簇电子功能的基本理解对于实现这一想法至关重要。
The correlated transfer of electrons one-by-one in metallic islands occurs when the energy e2/CT (e is electron charge, CT is total island capacitance) required to charge the island by a single electron is large relative to that supplied by thermal energy (kT). 1 Although single-electron tunneling (SET) has been investigated intensely since the early 1960s, the relatively large size of devices prepared photolithographically has demanded extremely low temperatures (typically subkelvin) to observe SET behavior. 2 Recent methods for synthesizing ligand-stabilized metal (Au, Ag, Pt) 3 and semiconductor (CdS, CdSe) nanoclusters with diameters of< 10 nm have enabled electronic characterization of tunnel junctions with capacitances of< 10-18 F; indeed, SET has now been observed in several nanoscopic systems at room temperature. 5 These experiments have renewed enthusiasm regarding the use of single-electron devices as data storage elements in which bits of information are represented by single electrons.A significant challenge to incorporating single-electron devices into nanoscale electronic circuitry is the sensitivity of SET currents to impurities which may reside on or near the nanoparticle. 1 Impurities introduce shifts in SET current-voltage (i-V) curves, making it unlikely that any two SET devices will be electronically equivalent. One proposed method for overcoming a current shift is to use a gate electrode to “reset” the device. Our group has been considering the possibility of employing particle capping ligands as “chemical gates” to manipulate SET currents. 1e Developing a basic understanding of how capping ligand chemistry affects nanocluster electronic function is of vital importance in implementing this idea.