Strain-induced formation of self-assembled InGaN/GaN superlattices in nominal InGaN films grown by plasma-assisted molecular beam epitaxy
Strain-induced formation of self-assembled InGaN/GaN superlattices in nominal InGaN films grown by plasma-assisted molecular beam epitaxy
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等离子体辅助分子束外延InGaN薄膜中应变诱导自组装InGaN/GaN超晶格的形成
DOI：
10.1103/physrevmaterials.5.124606
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发表时间：
2021-12-28
影响因子：
3.4
通讯作者：
Ahmadi, Elaheh
中科院分区：
文献类型：
--
作者：
Khan, Kamruzzaman;Sun, Kai;Ahmadi, Elaheh
在这项工作中，我们报告了在等离子体辅助分子束外延生长的标称InGaN薄膜中自发形成超晶格结构。获得了一个700 nm厚、结构质量优良的自组装In0.2Ga0.8N/GaN超晶格。在相似的生长条件下，研究了应变作为InGaN在ZnO衬底上生长形成自组装超晶格（SASL）结构的可能驱动力。利用光致发光光谱对SASL结构进行了光学表征。通过透射电子显微镜和原子探针层析成像进行了结构表征。利用高分辨率x射线衍射（XRD）和XRD互易空间图测定了InGaN薄膜的平均成分和弛豫度。我们认为在SASL结构中观察到的垂直相分离是由高温生长引起的，并因应变而加剧。这项工作为包括太阳能电池和光电探测器在内的各种应用提供了一种工程应变和生长InGaN厚膜的方法。
In this work, we report the spontaneous formation of superlattice structures in nominal InGaN films grown by plasma-assisted molecular beam epitaxy. A 700-nm-thick self-assembled In0.2Ga0.8N/GaN superlattice with excellent structural quality was achieved. Strain was studied as a possible driving force for the formation of selfassembled superlattice (SASL) structure by growth of InGaN on ZnO substrate using similar growth conditions. The SASL structures were optically characterized using photoluminescence spectroscopy. Structural characterization was conducted via transmission electron microscopy and atom probe tomography. High-resolution x-ray diffraction (XRD) and XRD reciprocal space map were utilized to determine the average composition and the degree of relaxation of InGaN films. We propose that the vertical phase separation observed in the SASL structure is caused by high-temperature growth and intensified by strain. This work provides a method for engineering strain and growth of thick InGaN films for a variety of applications including solar cells and photodetectors.