卷曲量子阱薄膜中的应变特性

Strain characteristics in a rolled-up nanomembrane containing quantum wells

嵌入非对称耦合量子阱(quantum wells)的纳米薄膜经过化学腐蚀后,在应变工程技术下卷曲成三维的管状结构,不同管径的微管其光学特性存在不同的模式,对应两种应变释放:单轴应变释放和双轴应变释放.为研究应变状态之间的内在联系以及影响应变状态的客观因素,实验上用不同浓度的HF酸腐蚀液对纳米薄膜牺牲层进行腐蚀并卷曲成三维管状结构.对微管荧光光谱的测试结果显示,微管的单轴应变释放和双轴应变释放不仅与衬底有关,还与微管卷曲的起始状态有关,在一定条件下两种应变可以相互转换.

The nanomembrane with embedded asymmetric coupled QWs by chemical etching was rolled-up into a three-dimensional tube structure via a strain-engineering route,it is found that there are two different modes of its optical properties and the modes can be expressed as two different strain release:uni-axial strain release and bi-axial strain release by the PL spectra obtained from microtubes with different diameters.In order to study the internal relationship between the strain state and the objective factors that affect the strain state,experimentally we used different concentration of HF acid etching solution to corrode the corresponding sacrificial layer of the nanomembrane which is rolled-up into a three-dimensional tube structure.Besides,the PL spectra of microtubes show that the uni-axial strain release and bi-axial strain release of microtubes are not only related to the influence of substrate,but also to the initial state of microtube and they can be transformed into each other under a certain condition.