Strain engineering as one of the most powerful techniques for tuning optical and electronic properties of Ill-nitrides requires reliable methods for strain investigation. In this work, we reveal, that the linear model based on the experimental data limited to within a small range of biaxial strains (< 0.2%), which is widely used for the non-destructive Raman study of strain with nanometer-scale spatial resolution is not valid for the binary wurtzite-structure group-III nitrides GaN and AlN. Importantly, we found that the discrepancy between the experimental values of strain and those calculated via Raman spectroscopy increases as the strain in both GaN and AlN increases. Herein, a new model has been developed to describe the strain-induced Raman frequency shift in GaN and AlN for a wide range of biaxial strains (up to 2.5%). Finally, we proposed a new approach to correlate the Raman frequency shift and strain, which is based on the lattice coherency in the epitaxial layers of superlattice structures and can be used for a wide range of materials.

应变工程作为调节 III 族氮化物光学和电子特性的最强大技术之一，需要可靠的应变研究方法。在这项工作中，我们揭示了基于实验数据的线性模型仅限于小范围的双轴应变（％3C 0.2％），该模型广泛用于纳米尺度空间应变的无损拉曼研究分辨率对于二元纤锌矿结构 III 族氮化物 GaN 和 AlN 无效。重要的是，我们发现随着 GaN 和 AlN 应变的增加，应变实验值与拉曼光谱计算值之间的差异也随之增加。本文开发了一种新模型来描述 GaN 和 AlN 中各种双轴应变（高达 2.5%）下应变引起的拉曼频移。最后，我们提出了一种关联拉曼频移和应变的新方法，该方法基于超晶格结构外延层中的晶格相干性，可用于多种材料。