【作者】 危兆玲；

【导师】 许并社；

【作者基本信息】 太原理工大学 ， 材料学， 2011， 硕士

【摘要】 Ⅳ-Ⅵ族化合物是一种具有立方结构窄禁带的半导体材料,尤其是PbS和PbSe具有优越的电学、光学性质,使其在红外光电探测、光伏转换材料、太阳能电池、非线性光学材料、光电器件、传感与检测等一些高新技术领域中有着广阔的应用前景。本论文主要以这两种半导体材料为研究对象,采用四种较为简便的工艺来合成这些材料。通过XRD、SEM、EDS和荧光光谱等测试手段对样品的结构、形貌及性能等进行表征,通过分析测试结果,进而优化制备工艺,提高产品性能。采用简单的化学气相沉积法(CVD)在不同的实验条件下制备了PbS微米立方体结构、PbS纳米线以及PbS网状纳米结构。通过考察反应温度和反应时间对产物形成的影响,得出制备PbS微米立方体结构的最佳实验条件为650℃反应10min。在制备PbS纳米线的过程中,升高反应温度和延长反应时间都使PbS由纳米线向微米立方结构转变；采用催化剂纳米Au有利于PbS纳米线的形成,而纳米Ag则不利于其形成。在制备PbS网状纳米结构的实验过程中发现,H2的流量对产物的形貌影响较大,在内口径为4.3cm的石英管内制备PbS网状纳米结构的最佳H2流量为1 sccm。通过荧光光谱分析,发现PbS纳米线的光致发光性能较PbS微米立方体和PbS网状纳米结构好,而PbS网状纳米结构的光致发光性能则是三者中最差的。采用微波辐射法和在表面活性剂十六烷基三甲基溴化铵(CTAB)的辅助下,采用高压釜制备出花状结构PbS和星形结构PbS,通过研究表面活性剂的加入量和反应时间对产物形成的影响,得到了快速制备花状结构PbS和星形结构PbS的最佳条件；同时通过对反应过程的分析,对花状结构PbS和星形结构PbS的形成机理进行了初步探讨。并通过对花状结构和星形结构PbS的荧光光谱分析,得出花状结构PbS的光致发光性能较星形结构好。本实验还借助微波辐射法采用冷凝回流装置制备了PbS纳米颗粒,与传统的制备方法相比,该方法装置简易、耗时短、产物的质量和产量都较高,是一种短时间制备半导体纳米材料的可行性方法。此外,采用简单的溶剂热法还制备了立方体结构PbS,通过对样品进行XRD和SEM分析表征,讨论了反应温度、反应时间以及硫源和铅源摩尔之比对PbS产物形貌的影响。由于生物诱导法环保、经济的特点近期倍受关注,本实验还尝试采用生物诱导法来制备PbSe纳米材料。本实验利用蛋膜在室温下的诱导作用合成了面心立方结构的PbSe纳米材料,通过考察硒源的陈化对产物形成的影响,得知硒源的陈化可使蛋膜纤维产生明显的包覆现象,而这种现象会使铅离子和硒离子之间产生更加有秩序的结合反应,进而得到分散性相对稳定的PbSe纳米材料。更多还原

【Abstract】 IV-VI compounds are semiconductor materials with a cubic structure and narrow band gap. PbS and PbSe semiconductor materials have a wide application prospect in the infrared optical detection, photovoltaic conversion, solar cells, nonlinear optical materials, optoelectronic devices, sensors and detectors, and some other high-tech fields as a result of their excellent electrical and optical properties. In this work, two kinds of semiconductor material were synthesized by four simple technological processes. A series of analytical methods including:X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and fluorescence spectrometer were used to characterize the crystalline phase, microstructure, and optical properties of as-synthesized samples. Based on experimental results and optimization of synthesis processes, the properties of products were further improved.PbS micron cube structure, PbS nanowires, and PbS nano-structural network were prepared via chemical vapor deposition (CVD) under different experimental conditions. Through studying the effects of reaction temperature and reaction time on the products, the optimum experimental conditions were found, under which the micro-nano cube structural PbS was prepared at a reaction temperature of 650℃for 10min. For PbS nanowires preparation, elevated reaction temperature or prolonged reaction time result in a change for PbS from nanowires to micrometer cubic structure; nano-Au catalyst was more favorable to the formation of PbS nanowires than the nano-Ag. Flows of H2 had impact on the network structure of PbS products and the optimum H2 flow was 1sccm for preparing PbS network nanostructures in the quartz tube whose diameter is 4.3cm. We found that photoluminescence properties of PbS nanowires was better than PbS micron cube structureand PbS nano-structural network, and the photoluminescence of PbS nano-structured network was the weakest among the three.Through studying the effects of surfactant and reaction time on product formation, the flower-like PbS and star-like PbS were prepared via microwave method in an autoclave with the assistance of cetyltrimethylammonium bromide (CTAB). The optimal conditions of rapid preparation for flower-like structural PbS and star structural of PbS were obtained. Through the analysis of the reaction processes, the formation mechanisms for the flower structural PbS and star structural PbS were discussed. And photoluminescence properties of the flower-like structure of PbS and star structural of PbS were discussed by fluorescence spectrometer and photoluminescence properties of star-shaped structure PbS was weaker. In addition, PbS nanoparticles were prepared in a condensate reflux device under the assistance of microwave radiation. Compared with traditional preparation methods, this method showed advantages such as simple devices, short time-consuming, high quality and yield. This is a feasible preparation method for semiconductor nanomaterials.The cube PbS was prepared by solvothermal method, microstructures and crystalline structures of as-synthesized PbS products were characterized and analyzed by field emission scanning electron microscopy, and X-ray diffraction. The effects of reaction temperature, reaction time, and the source molar ratio of sulfur to lead on the morphology were discussed.As the biologically induced mothed is getting much attention for its environmental protection and economic benefits, egg membrane was introduced into this work to synthesize face-centered cubic structural PbSe at room temperature. Meanwhile, the effect of aging of selenium source solution on product formation was investigated. The aging of Se source resulted in obvious encapsulation of the egg membrane, and this phenomenon led to orderly binding reaction of lead ions and selenium ions so that PbSe nano-materials were synthezised with a relatively good dispersion stability.更多还原