【作者】 何星伟；

【导师】 朱长飞；

【作者基本信息】 中国科学技术大学 ， 材料物理与化学， 2011， 硕士

【摘要】 当前,随着化石能源的日益枯竭以及环境污染等问题迫使人们寻求可替代的再生新能源。而且光伏产业正在成为各国经济发展的战略新兴产业。其中作为第三代的薄膜太阳能电池铜铟镓硒(CIGS)也在逐渐产业化。然而,在如何进一步提高电池效率以及大规模产业化确保重复性方面还存在很多障碍。铜铟镓硒太阳能电池涉及很多层薄膜材料的制备,工艺复杂,每一层材料的制备都会对电池性能有影响。本论文就化学浴沉积法合成缓冲层材料CdS薄膜的工艺及其生长机制进行了一些研究。化学浴沉积法制备CdS薄膜主要涉及到两种机制:ion-by-ion和cluster-by-cluster;两种机制生长出来的薄膜具有不同的物理性质。条件的改变(如温度、浓度、pH值、沉积时间等)会对薄膜的生长速率,表面形貌,晶体结构,光学性质等产生很大的影响。由于反应物浓度和pH值的影响在文献中已经有很多报道,本文着重选取了沉积温度和时间对薄膜性能的影响。在60oC、70oC、80oC、90oC条件下,沉积不同时间得到CdS薄膜,对其进行SEM、XRD以及OT表征,根据Urbach公式计算带隙。随着沉积温度的增加,薄膜生长速率加快直到达到饱和厚度,然后由于剥蚀,进一步反应薄膜厚度会降低。本文提出,不论温度,薄膜的生长一开始由ion-by-ion机制占主导,随着时间的进行,cluster-by-cluster机制控制着反应。并从表面形貌,晶体结构,带隙值变化等方面对这一生长机制作出了合理的解释。另外,尽管铜铟镓硒太阳能电池在未来几年仍有很大发展潜力,但由于铟在地壳中的分布量比较小,其最终势必会受到限制。类似铜铟镓硒(CuInxGa1‐xSe2)薄膜的铜锌锡硫薄膜(Cu2ZnSnS4)正在引起实验室的广泛关注。它们具有相同的黄铜矿晶体结构,类似的光电性质。铜锌锡硫薄膜的直接带隙为1.4ev‐1.5ev,其中的各种基本元素在地壳中分布广泛且无毒。且目前采用共蒸发法,效率为6.77%的CZTS太阳能电池已经被制备出。因此,本论文在非真空法制备CZTS薄膜方面也做了一些初步的探索。利用Sol‐Gel法合成金属前驱体,在氢气氛中退火,最后硫化的过程得到CZTS薄膜。更多还原

【Abstract】 Currently, as fossil energy exhausting and pollution problems, people force to seek alternative regeneration new energy. And the PV industry is becoming the strategic economic development of all countries in new industries. At the same time, Copper Indium Gallium Selenium thin film solar cells(CIGS) is also gradually in the industrialization. However, there are many obstacles that how to further improve the efficiency of the cells and ensure repeatability when large-scale industrialization. CIGS solar cells involves many film materials’preparation, which process is complex. Each layer materials for the preparation will have influence on the battery performance. In our this paper, we research the process and growth mechanism of CdS film deposited by Chemical Bath Deposition (CBD) as the buffer layer material.As deposition of CdS films by CBD, it mainly relates to the two film growth mechanisms, ion-by-ion and cluster-by-cluster. Different growth mechanism affects the properties of the fabricated film. The change of conditions (such as temperature, PH value, reactant concentration, composition of the solution and the deposition time) generates a lot of influence on the growth rate of films, crystal structure and surface morphology, optical properties. Because the influence of the concentration of reactants and pH value in the literature has so many reports, we emphatically chose deposition temperature and time to research the properties of film.CdS thin films were got by Chemical-bath-deposited at 60oC、70oC、80oC、90oC. Through analysis of planar and cross-section SEM, X-ray diffraction XRD, optical transmittance and bandgap value analysis, we explain film growth mechanism. Independent of the deposited-temperature, the growth was mainly controlled by the ion-by-ion growth mechanism in the beginning of the film deposition, and then the cluster-by-cluster mechanism came to be dominant.In addition, we also made some preliminary exploration in synthesising Copper zinc tin sulfur thin film (CZTS) by non-vacuum chemical method. Prepare the metal precursor using sol-gel method,and then sulfurizing.更多还原