【作者】 郭传华；

【导师】 刘美英；

【作者基本信息】 辽宁师范大学 ， 无机化学， 2010， 硕士

【摘要】 FeS₂（pyrite）具有合适的带隙宽度（0.95 eV）及高的光吸收系数(λ≤700nm,α≥5×10⁵cm^-1),目前已成为薄膜太阳能电池的最佳吸收材料之一。但FeS₂（marcasite（）0.3 eV）的存在大大影响了FeS₂（pyrite）的性能。具有黄铁矿型结构的硫化镍也是近年来日益引人注目的材料,然而它存在α-Ni_3+xS₂、β-Ni₃S₂、Ni₄S_3+x、Ni₆S₅、Ni₇S₆、Ni₉S_s、α-NiS、β-NiS、Ni₃S₄及NiS₂等多种物相。因此控制反应过程,合成单一物相的硫化铁和硫化镍纳米晶成为当前研究的热点。本工作采用溶剂热技术,通过调控原料摩尔比、反应温度、反应时间及添加表面活性剂来调控硫化物的物相组成及形貌结构,取得以下主要结果:以硝酸铁和硫脲作铁源及硫源、乙二醇作溶剂,利用溶剂热技术合成了Fe3S₄和Fe_1-xS纳米晶;在表面活性剂PVP的协助下合成了FeS)2（pyrite）纳米晶,并有效抑制了pyrite其它伴生相尤其是marcasite的形成。通过调控原料的摩尔比、反应温度及反应时间可实现对产物晶相和形貌的有效控制。以硝酸镍和硫脲作镍源及硫源、乙二醇作溶剂,采用溶剂热技术制备了Ni₃S₂和α-NiS纳米晶;在表面活性剂PVP协助下合成了立方相NiS₂纳米晶。丙烯酰胺能够调控硫化镍的晶相组成及形貌结构:随丙烯酰胺量的增加,产物从立方相NiS₂实心球转变为六方相α-NiS实心球（丙烯酰胺:硫脲=25:1）,最终转变为斜方相β-NiS空心球（丙烯酰胺:硫脲=200:1）。利用溶剂热技术尝试性地合成了硫化铁薄膜,该技术反应条件温和、产物纯度高、分散性好,而且物相的形成、粒径大小和形貌均易控制,是合成光电薄膜的一种低成本方法。更多还原

【Abstract】 FeS₂（pyrite） has been considered as one of the best absorption materials for thin film solar cell due to its suitable band gap （0.95 eV） and high light absorption coefficient (λ≤700nm,α≥5×10⁵cm^-1). However, the coexistence of FeS₂（marcasite） with a direct band gap （0.3 eV） significantly affects the properties of FeS₂（pyrite）. Nickle sulfide with pyrite structure is also an interesting material of research and is currently attracting much attention. However, nickle sulfide has several crystalline phases includingα-Ni_3+xS₂,β-Ni₃S₂, Ni₄S_3+x, Ni₆S₅, Ni₇S₆, Ni₉S₈,α-NiS,β-NiS, Ni₃S₄ and NiS₂. Therefore, it is a challenging and interesting topic of research to synthesize iron sulfide and nickel sulfide with single phase by controlling the reaction process. This thesis focuses on the phase and morphology control of iron sulfide and nickel sulfide via a solvothermal process by changing experimental parameters such as the molar ratio, reaction temperature and reaction time, and by the addition of appropriate surfactants.A series of nanocrystalline iron sulfide has been successfully prepared via the reaction of Fe（NO₃）₃·9H₂O with NH₂CSNH₂in ethylene glycol in the temperature range of 200²40°C. Two single phases of Fe3S₄ and Fe_1-xS was obtained without surfactant. Using PVP as surfactant, Pyrite FeS₂ was obtained and marcasite FeS₂ was effectively inhibited. We present some results on the influence of reactant molar ratio, reaction temperature and time, and the kind of surfactants on the formation of the single-phase pyrite FeS₂ powder.Two single phases of Ni₃S₂ andα-NiS nanocrystals has been successfully prepared by the reaction of Ni（NO₃）₂·4H₂O with NH₂CSNH₂in ethylene glycol via a solvothermal process in the temperature of 160²20°C. It was found that both the temperature and the molar ratio of nickel nitrate to thiourea put a significant effect on the phase and morphology of nickel sulfide powders. In addition, Single phase cubic NiS₂ was obtained via a PVP-assisted solvothermal route. More interestingly, the phase and morphology of nickel sulfide nanocrystals could be adjusted by the addition of acrylamide as surfactant. With the amount of acrylamide increase, the products transformed from the cubic phase of NiS₂ solid ball into the rhombohedral phase ofα-NiS （acrylamide: thiourea=25:1） solid ball, eventually transformed into hexagonalβ-NiS （acrylamide: thiourea = 200:1） hollow spheres.FeS₂ thin film was deposited onto ITO glass substrates via a solvothermal method, which is mild, convenient and easy to handle compared with the conventional coating technique.更多还原