CdS/CdTe interface analysis by transmission electron microscopy
CdS/CdTe interface analysis by transmission electron microscopy
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DOI：
10.1116/1.582393
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发表时间：
2000-07-01
期刊：
影响因子：
--
通讯作者：
Kazmerski, LL
中科院分区：
文献类型：
--
作者：
Dhere, RG;Al-Jassim, MM;Kazmerski, LL
基于CdTe的多晶太阳能电池是陆地光伏应用的主要候选者。尽管六方晶系CdS和立方晶系CdTe之间存在较大的晶格失配，但仍然获得了高效率的器件。本文采用化学浴沉积法在Si衬底上沉积CdS，采用近距离升华法沉积CdTe。CdS/CdTe界面的化学性质、结构特性及其对制造参数的依赖性，例如，衬底温度（475-600 ℃）和沉积后CdCl 2热处理。此外，CdS的结晶度对界面结构缺陷的影响进行了研究。界面的小斑点能量色散谱显示了相当数量的硫在碲化镉。硫的浓度，在一般情况下，在具有较高密度的结构缺陷的晶粒和晶界处较高。CdTe薄膜中的平面缺陷密度随衬底温度的升高而增加，而穿透位错密度随衬底温度的升高而降低。界面分析表明，在CdS上沉积的CdTe薄膜中的晶体缺陷的大部分产生在界面处。CdS的结晶度对界面缺陷的产生没有重大影响。(C)2000年美国真空学会。【S0734-2101（00）17101-0】。
CdTe-based polycrystalline solar cells are leading candidates for terrestrial photovoltaic applications. High efficiency devices have been obtained despite large lattice mismatch between hexagonal CdS and cubic CdTe. In the present work, CdS was deposited by chemical bath deposition on Si substrates, and CdTe was deposited by close spaced sublimation. The chemical nature of the CdS/CdTe interface, structural properties, and their dependence on the fabrication parameters, e.g., substrate temperature (475-600 degrees C) and postdeposition CdCl2 heat treatment, were analyzed. In addition, the effects of crystallinity of CdS on the interface structural defects were examined. Small spot energy dispersive spectroscopy of the interface revealed a considerable amount of sulfur in CdTe. The concentration of sulfur, in general, was higher ill the grains with higher density of structural defects and at the grain boundaries. The planar defect density in CdTe films increased with substrate temperature, whereas the threading dislocation density decreased. Interface analysis showed that the majority of the crystalline defects in the CdTe films deposited on CdS were generated at the interface. The crystallinity of CdS did not have a major influence on the interface defect generation. (C) 2000 American Vacuum Society. [S0734-2101(00)17101-0].