【作者】 高炜；

【导师】 刘瑞泉；

【作者基本信息】 新疆大学 ， 物理化学， 2013， 硕士

【摘要】 离子液体作为绿色新型溶剂，具有电势窗口宽，溶解能力强，室温下稳定等优点，可作为电解液应用于金属的电沉积工艺中。Cu(In,Ga)Se2(CIGS)薄膜电池是近年来光伏研究热点，可在离子液体中通过电沉积工艺制备，其中Cu与In元素是中的组成元素，本文针对Cu2+、In3+在离子液体中电化学行为进行研究，旨在探索大面积、高质量电沉积制备Cu-In薄膜，为CIGS薄膜的研究与开发做探索工作。本文选择氯化1-丁基-3-甲基咪唑(BMIC)离子液体为溶剂，并将乙二醇(EG)加入至BMIC中以代替水性溶剂避免工作电极析出氢气，且能提高BMIC的电导率，降低BMIC的粘度，以达到Cu、In共沉积为思路。系统的研究了加入EG后BMIC离子液体的粘度，电导率和电势窗口，以及温度对于粘度与电导率的影响。将CuCl2与InCl3溶于BMIC-EG中，并通过循环伏安法研究其电化学行为。研究结果表明，EG的加入能够降低BMIC的粘度，增加其电导率，且EG与BMIC的摩尔比为1:3时，电导率不再随粘度的降低而升高。通过循环伏安曲线可以看出，Cu2+在BMIC-EG中Pt电极上的电还原过程分为两个不可逆过程，且受扩散控制，属于欠电势沉积；而In3+在BMIC-EG中Pt电极上的还原经历为In(III)→In，为不可逆三电子转移过程，循环伏安曲线中出现电流滞环属于过电势沉积，且成核过程符合三维瞬时成核。通过电沉积获得了以Cu为基底的Cu镀层与In镀层。本文还测定了在BMIC-EG中一步恒电位沉积制备Cu-In合金，研究结果表明，In3+的还原电位较负，所需沉积电位也较负。且Cu-In镀合金膜主要是由Cu4In构成，其中In元素的含量与电解液中In3+的浓度有关，在较负的沉积电位下得到的Cu-In镀层形貌为大颗粒团簇结构。更多还原

【Abstract】 Ionic liquid, as a new green solvent, is characterized by its wide potentialwindow, strong solvency and good stability at room temperature. It can serve as anelectrolyte in the electrodeposition of metal. The thin-film cell, Cu(In,Ga)Se2(CIGS),is a hot topic in photovoltaic research in recent years. It can be produced throughelectrodeposition in ionic liquids, in which Cu and In are both elements of CIGS.Thus, the present thesis aims to study the electrochemical behaviors of Cu2+and In3+in ionic liquids, in the hope of finding out how to produce Cu-In thin films in largequantity and good quality.1-butyl-3-methylimidazolium chloride (BMIC) was utilized as the ionic liquid inthis thesis. Ethylene glycol (EG) was added into BMIC to substitute aqueous solventand to prevent leak of hydrogen from electrode, which also could extend thedeposition voltage window and ensure the electrodeposition of both Cu and In. Thethesis systemically studied the conductivity, potential window and viscosity of thesolvent when BMIC had been added with EG. The effect of temperature on theviscosity of the solvent was also studied. Beside, CuCl2was merged into BMIC-EGto study its electrochemical behaviour by cyclic voltammetry.The results of the research are as follows: the addition of EG could reduce theviscosity of BMIC and increase the conductivity. But the conductivity does not go upwith the decreasing of viscosity as the mole ratio of EG and BMIC reaches1:3. Thecyclic voltammetry curves reveal that the reduction of Cu2+on the Pt electrode inBMIC-EG consists of two irreversible processes under the control of diffusion. Theyare underpotential deposition. The reduction of In3+on the Pt electrode in BMIC-EGis an irreversible three-electron transfer, going through the process of In（III）→In.The current hysteresis appeared in the cyclic voltammetry curves is the overpotentialdeposition, whose nucleation corresponds to the three-dimensional instantaneousnucleation. Electrodeposition has produced copper coating and In coating, with Cu assubstrate.The present thesis also has made tests to produce Cu-In alloy by one-steppotentiostatic electrodeposition. The results indicate that reduction potential of In3+ turns more negative and the needed deposition potential turns more negative as well.Plating alloy film of Cu-In is mainly composed of Cu4In, in which the content of In islinked to the viscosity of In3+in electrolyte. The morphology of Cu-In coating gainedin more negative deposition potential demonstrates large particle clusters.更多还原