The fabrication of Sn-Se compounds, at room temperature by electrochemical atomic layer epitaxy (EC-ALE) is reported. EC-ALE involves the use of surface limited reactions to forrn atomic layers of the elements making up a compound (Sn and Se) in a cycle. Cyclic voltammograms were used to determine approximate deposition potentials for each element. The amperometric I-t method and differential pulse anodic stripping voltammetry were used to deposit and study the processes involved in a continuous cycling deposition which were used to form thin films of the compound. Through the analysis of the I-t transients and the stripping voltammograms it is possible to establish the formation of Sn-Se compounds. Taking into account the charges involved in the I-t deposition process, a general reaction scheme that considers the formation of SnSe2, SnSe2-x and SnSe compounds is proposed.

在具有催化还原活性的金电极表面，以水合肼为还原剂，在pHlO.5酒石酸钾钠溶液中，通过化学镀方法，选择性地在金电极表面沉积了单层结构的铜膜。用开路电位一时间谱技术（op-t）、循环伏安法（CV）和微分脉冲伏安法（DPV）表征了该溶液还原法对铜进行选择性富集的机理和效果。证明在多种金属离子共存的复杂溶液体系中，可以避免其它离子的干扰，使铜选择性地富集到金电极表面。化学镀浴中富集到金电极表面的单层铜膜溶出电流与cu2+的浓度在3×10-6～l×10-4mol、L范围内呈线性关系。该法已用于矿样中铜的还原富集、分离和测定，分析结果与电感耦合等离子体发射光谱法（ICP/AES）作了比较，结果满意。

用循环伏安法研究了Sn2+在金盘电极上的欠电位沉积。在特别提纯的1mol/L HCl支持电解质溶液中，Sn2+在金盘电极上可以产生清晰的欠电位沉积峰和本体沉积峰.基于Au/Sn欠电位体系优良的电化学特性，发展了一种选择性好、灵敏度高的电化学分析方法。Sn2+浓度在1.96×10-10～2.91×10-8mol/L范围内与峰电流有线性关系。连续7次测定1.0×10-9mol/L Sn2+得到的相对标准偏差为5.06%。该方法已用于实际样品的测定，所得结果与原子发射光谱（ICP—AES）所得数据相吻合。

The microcontamination process of silver onto p-type crystalline silicon (111) in a solution of 0.01molL-1 AgNO1 at room temperature was inves-tigated by studying the anodic stripping behavior using cyclic voltammetry (cv). This paper shows that the rate of Ag deposition is rapid and that deposition is almost fully accomplished within 1S. Calculating the surface coverage(r) for 1S, 10min, or 1h immersion based on the CV curves demonstrated that the silver layer was only a monolayer.

A method of electroless silver deposition on silver activated p-type silicon (111) wafer was proposed. The silver seed layer was deposited firstly on the wafer in the solution of 0.005mol/L AgNO3+0.06mol/L HF. Then the silver film was electrolessly deposited on the seed layer in the electroless bath of AgNO3+NH3+acetic acid+NH2NH2 (pH 10.2). The morphology ofthe seed layer and the silver films prepared under the condition ofthe different bath compOSition was compared by atomic force microscopy. The reflectance of the silver films with different thickness was characterized by Fourier transform infrared spectrometry. The experimental results indicate that the seed layer Dossesses excellent catalytic activity toward electroless silver deposition and rotating of the silicon wafer during the electroless silver deposition could lead to formation of the smoother silver film.

This investigation first proposed that open-circuit potential vs time (OCP-t) is a novel nonlinear potential step controlled by redox reaction and nucleation. A novel thermodynamic model of OCP-t is obtained for electroless deposition of Ni on Pd-activated p-type silicon 100. Thermodynamic transient properties such as capacity of double layer C, surface charge density q, interfacial tension, and resistance of chemical reaction Rr are calculated. Results show that the variation of OCP is dependant on the interfacial double layer. The breakdown and rearrangement of the double layer causes surface charge density step, which triggers momentary nucleation of Ni on the substrate. Results also show that reductant pulses would be an effective way to speed nuclei growth.

This work describes a study of the underpotential deposition (UPD) of Sn2+ on a polycrystalline gold disc electrode using cyclic voltammetry (CV) and chronocoulometry (CC). Sn2+ ions showed well-defined peaks from UPD and UPD stripping (UPD-S) in 1 mol/L HCl solutions, while bulk deposition (BD) and BD stripping (BD-S) of the ions were also observed. The measured UPD shifts, DEUPD, between the UPD-S and the BD-S peaks were more than 200 mV. The UPD charge and the surface coverage of tin were measured by CC. A new method for determining Sn2+ was therefore developed, based on the excellent electrochemical properties of the Au/Sn UPD system. A plot of the UPD-DPASV (differential pulse anodic stripping voltammetry) signal versus the Sn(II) concentration was obtained for [Sn(II)] of 1.98

A novel method of silver electroless deposition on p-Si(100) wafer under the condition of the centrifugal force was developed. The Ag seed layer was firstly prepared on the wafer in a solution of 0.005 mol/l AgNO3+0.06 mol/l HF then the silver film was electrolessly deposited in another electroless Ag bath under the centrifugal fields. The morphology of the prepared silver film was characterized by atomic force microscopy. The crystal orientation of the film was characterized by X-ray diffraction. The experiment results show that the silver film obtained under the condition of the strong centrifugal force is smoother and denser.

A new method for silver electroless deposition on Si(100) wafer, based on the silver itself as the seed layer, was developed. The seed layer was first deposited onto the etched wafer surface in an acidic solution of 0.005 mol 1-1 AgNO3+0.06 mol 1-1 HF. Then the silver thin film was electrolessly deposited upon the seed layer in the electroless bath of AgNO3+NH3+acetic acid+NH2NH2 (pH 10.2). The NH2NH2 was taken as the reducing agent. The morphology of the seed layer and the silver film were characterized by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray analysis (EDX). The experimental results indicated that the seed layer showed excellent catalytic function for silver electroless deposition.

The anodic stripping behavior of the Ag seed layers on a p-silicon (100) wafer was studied by cyclic voltammetry (CV). The seed layers were prepared by immersing the silicon wafer in a solution of 0.005 M AgNO3+0.06 M HF at room temperature. Then the layer adhered wafers were used as the work electrodes. The oxidation energy of the Ag monolayer based on the Si-Ag combination was observed and the oxidation energy of the Ag multilayer based on the Ag-Ag combination was also found.