【作者】 蒋益明；

【导师】 华中一； 李劲；

【作者基本信息】 复旦大学 ， 物理电子学， 2006， 博士

【摘要】 传质特性是材料的基本性质之一，在电子器件的制造、工艺、失效分析与可靠性评估等诸多应用领域中，均涉及到传质问题。近年来由于金属有机物复合薄膜体系在有机发光、光电信息存贮、纳米电子器件等领域中的广泛应用，使得金属与有机物双层膜之间的传质过程成为一个非常值得关心的重要科学问题。澄清薄膜中的传质规律对特殊结构膜的制备、可控纳米结构的实现、薄膜结构的稳定性以及薄膜应用与失效分析等都具有重要意义。本文选取电子亲合力差别较大的两种组元(Ag与TCNQ)制备成金属／有机双层膜体系，在确保其化学配比和物理化学稳定性的基础上，讨论了金属有机络合物薄膜的电学性能；对不同厚度膜层在化学位梯度与自建电场作用下的传质行为进行了实验研究和理论分析；系统考察了湿度对传质过程的影响，揭示了其中的特殊现象和规律，深入探讨了传质过程的机制。所得结果对于金属有机双层膜的快速制备，相关膜层的失效分析具有重要指导作用，主要结果如下：1．采用分层蒸发技术，利用透射光谱作标定，得到化学配比良好的Ag／TCNQ双层膜体系。2．采用透射光谱作为表征手段，利用扩散反应对Ag／TCNQ双层膜的传质行为进行研究，发现超薄膜情况下的异常加速传质现象，厚膜情况下传质常数k=3.62x10-16cm2／s；薄膜情况下至少可增加1个数量级。3．从场致迁移理论出发分别建立了隧穿(薄膜)与非隧穿(厚膜)条件下的金属离子传质模型，解释了厚膜与薄膜的传质实验结果，指出厚膜情况下传质过程符合抛物线规律；而在薄膜情况下传质过程符合反对数规律。4．采用不同条件控制环境中湿度，观测Ag／TCNQ双层膜传质过程。发现湿度对传质有显著的加速作用，用电化学模型对该加速现象给出理论解释，指出在湿条件下，传质由干条件下的固体化学扩散机制转变为水溶液中的电化学机制。5．在湿度控制的Ag／TCNQ双层膜传质研究中，发现了传质速度与湿度的反比规律，从表面吸附的相关理论提出了湿度控制传质模型，证明湿环境加速传质的控制步骤为水分子在有机膜上的吸附。6．对不同膜厚样品进行传质研究中，用毛细吸附理论推算出Ag／TCNQ膜表面等效孔半径为15(?)，且基本不随膜厚改变。7．在认识到了湿度对Ag／TCNQ双层膜传质过程中的加速作用这一现象及其电化学机理后，对原有的真空镀膜方法进行了改进，提出了一种制备金属有机络合物电双稳薄膜的新方法，其特点是结合了真空镀膜方法和电化学方法制备超平纳米薄膜，使得到的薄膜即具有真空方法表面形貌好，性能稳定的优点，又同时具备化学方法组分配比严格的优点。更多还原

【Abstract】 Elementary transport behavior is one of the basic characters of material. It is involved in many fields, including electrical device manufacture, reliability and failure analysis. In recent years, metal organic complex thin films are widely used in many fields such as organic luminescence, ultra high density storage film, nanoelectronics devices and so on. Therefore the transport behavior between metal and organic film is a remarkable topic. To clarify the law of transport in thin film will have great impact on both science and practice.In this paper, two kinds of material with different electrical affinity (Ag and TCNQ) are chosen and prepared to bi-layer film. The transport behavior of this system is studied experimentally and theoretically. Special phenomena and rules are revealed and the mechanism of transport process is discussed. All results can be a useful guidance to fast preparation of the relevant films and failure analysis. The main findings are as follow-ups:1. Ag/TCNQ bi-layer thin film with good stoichiometry and stable electrical character is obtained by alternately vacuum deposition.2. The transport behavior in Ag/TCNQ bi-layer film is studied through solid state chemical diffusion reaction by using transmission spectrum to monitor the process. An anomalously fast transport phenomenon is observed when the film is ultra thin.3. Tunneling model and non-tunneling model are established respectively based on the field induced migration theory. Results from theoretical analyses indicate that the transport process accords with parabola when the film is relatively thick, while matches inverse logarithm when the film is ultra thin.4. The transport process of Ag/TCNQ bi-layer under different humidity condition is studied carefully. It is found that environmental humidity can greatly accelerated the transport process. A mechanism of electrochemistry is proposed to explain this phenomenon. An inverse proportional relationship between transportspeed and humidity is found out. A humidity controlled transport model is proposed based on surface adsorption theory.5. The equivalent pore radius of Ag-TCNQ is deduced to be 15 (?) based on capillary condensation theory, which does not vary with film thickness.6. A new method by combining vacuum deposition and electrochemical reaction is developed to prepare metal-organic thin films. Ag-TCNQ film which is prepared by this method shows an electrical bistable characteristic with good homogeneity. It also has a smooth surface morphology and a stoichiometric composition. This new method is helpful to make micro-electronics devices, molectroics devices and high density memories.更多还原