Deposition and characterization of Cd1-xMgxTe thin films grown by a novel cosublimation method
Deposition and characterization of Cd1-xMgxTe thin films grown by a novel cosublimation method
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DOI：
10.1116/1.4863314
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发表时间：
2014-03-01
影响因子：
2.9
通讯作者：
Sampath, Walajabad S.
中科院分区：
文献类型：
--
作者：
Kobyakov, Pavel S.;Moore, Andrew;Sampath, Walajabad S.
利用CdS/CdTe结构的光伏电池在过去的几年中已经有了很大的改进。尽管最近的进展，CdS/CdTe电池的效率仍然显着低于他们的肖克利-奎塞尔极限。CdTe基三元合金薄膜如Cd_（1-x）Mg_xTe（CMT）可用于提高CdS/CdTe光伏电池的效率。高禁带宽度的Cd_（1-x）Mg_xTe薄膜可以作为叠层结构顶电池的吸收层，也可以作为CdS/CdTe电池的电子反射层。提出了一种新的共升华法制备存款CMT薄膜。这种方法可以存款CMT薄膜的带隙范围为1.5至2.3 eV。共升华方法快速，可重复，可扩展到大面积，使其适合实施到大规模生产。沉积的CMT膜的表征，与x从0到0.35的变化，揭示了通过能量色散X射线光谱测量的Mg含量和光学带隙之间的线性关系。掠射角X射线衍射（GAXRD）测量的Cd 1-xMgxTe薄膜显示了类似于CdTe的锌-碲化物结构。此外，增加Mg含量降低晶格参数和晶粒尺寸。GAXRD显示薄膜沉积后处于温和的张力下。(C)2014年美国真空学会。
Photovoltaic cells utilizing the CdS/CdTe structure have improved substantially in the past few years. Despite the recent advances, the efficiency of CdS/CdTe cells is still significantly below their Shockley-Queisser limit. CdTe based ternary alloy thin films, such as Cd1-xMgxTe (CMT), could be used to improve efficiency of CdS/CdTe photovoltaic cells. Higher band gap Cd1-xMgxTe films can be the absorber in top cells of a tandem structure or an electron reflector layer in CdS/CdTe cells. A novel cosublimation method to deposit CMT thin films has been developed. This method can deposit CMT films of band gaps ranging from 1.5 to 2.3 eV. The cosublimation method is fast, repeatable, and scalable for large areas, making it suitable for implementing into large-scale manufacturing. Characterization of as-deposited CMT films, with x varying from 0 to 0.35, reveals a linear relationship between Mg content measured by energy dispersive x-ray spectroscopy and the optical band gap. Glancing angle x-ray diffraction (GAXRD) measurements of Cd1-xMgxTe films show a zinc-blende structure similar to CdTe. Furthermore, increasing Mg content decreases the lattice parameter and the grain size. GAXRD shows the films are under mild tension after deposition. (C) 2014 American Vacuum Society.