Surface and interface of epitaxial CdTe film on CdS buffered van der Waals mica substrate
Surface and interface of epitaxial CdTe film on CdS buffered van der Waals mica substrate
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DOI：
10.1016/j.apsusc.2017.03.260
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发表时间：
2017-08
影响因子：
6.7
通讯作者：
Y. -. Yang;Lucas J. Seewald;D. Mohanty;Yiping Wang;L. H. Zhang;K. Kisslinger;W. Xie;Jian Shi;I. Bhat;Shengbai Zhang;T. Lu;Gwo-Ching Wang
中科院分区：
文献类型：
--
作者：
Y. -. Yang;Lucas J. Seewald;D. Mohanty;Yiping Wang;L. H. Zhang;K. Kisslinger;W. Xie;Jian Shi;I. Bhat;Shengbai Zhang;T. Lu;Gwo-Ching Wang
单晶CdTe薄膜是光电子器件应用的理想材料。产生具有高结晶度的膜的重要策略是通过在适当的单晶衬底上外延生长。我们报道了在CdS/云母衬底上外延CdTe薄膜的金属有机化学气相沉积。采用热蒸发法在云母表面生长了CdS外延膜。由于弱的货车德瓦耳斯力，尽管CdS和云母之间的界面晶格失配非常大（21-55%），仍然实现了外延。用原子力显微镜对云母、CdS和CdTe的表面形貌进行了定量分析。采用独特的反射高能电子衍射表面极图技术表征了CdTe和CdS薄膜的近表面结构、取向和织构。用X射线极图技术和透射电子显微镜对CdTe和CdS薄膜与云母的界面进行了表征。异质外延薄膜叠层的面外和面内外延分别为CdTe（111）//CdS（0001）//云母（001）和[1 <$2 1 <$$>] CdTe//[1 <$100] CdS//[010]云母。所测得的光致发光（PL），时间分辨PL，光响应，和霍尔迁移率的CdTe/CdS/云母表示质量膜。利用货车德瓦耳斯表面外延生长CdTe/CdS薄膜为红外成像和太阳能电池应用提供了一种替代策略。
Single crystal CdTe films are desirable for optoelectronic device applications. An important strategy of creating films with high crystallinity is through epitaxial growth on a proper single crystal substrate. We report the metalorganic chemical vapor deposition of epitaxial CdTe films on the CdS/mica substrate. The epitaxial CdS film was grown on a mica surface by thermal evaporation. Due to the weak van der Waals forces, epitaxy is achieved despite the very large interface lattice mismatch between CdS and mica (∼ 21–55%). The surface morphology of mica, CdS and CdTe were quantified by atomic force microscopy. The near surface structures, orientations and texture of CdTe and CdS films were characterized by the unique reflection high-energy electron diffraction surface pole figure technique. The interfaces of CdTe and CdS films and mica were characterized by X-ray pole figure technique and transmission electron microscopy. The out-of-plane and in-plane epitaxy of the heteroepitaxial films stack are determined to be CdTe (111)//CdS (0001)//mica (001) and [1¯ 2 1¯] CdTe//[1¯ 100] CdS//[010] mica, respectively. The measured photoluminescence (PL), time resolved PL, photoresponse, and Hall mobility of the CdTe/CdS/mica indicate quality films. The use of van der Waals surface to grow epitaxial CdTe/CdS films offers an alternative strategy towards infrared imaging and solar cell applications.