Abstract Nanoindentation was used to investigate the mechanical parameters of GaAs/AlAs Distributed Bragg Reflectors. Such heterostructures are commonly employed in surface-emitting optoelectronic devices as LED or lasers. The investigation was carried for fully pseudomorphic AlAs/GaAs heterostructures and compared with bulk GaAs. The nanoindentation tests with sharp (Vickers) and spherical tip were conducted, and pop-in events were observed. We show that below pop-in load, the response of both materials is similar i.e., elastic parameters of the heterostructure and GaAs are practically the same. However, the pop-in events take place at higher loads for heterostructures than for GaAs. This in turn indicates that the heterostructure has a higher resistance to damage. For both materials, the pop-in load depends on loading rate. The possible mechanisms of pop-in are discussed. In the elastic-plastic stage (after pop-in), the heterostructure exhibits lower stiffness and lower hardness than GaAs does. The surface cracks that are generated in the heterostructure during the indentation test continue to grow even when the load is removed.

中文翻译：

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在 GaAs 衬底上生长的 GaAs/AlAs 分布式布拉格反射器的纳米压痕

摘要 采用纳米压痕技术研究了GaAs/AlAs分布式布拉格反射器的力学参数。这种异质结构通常用于表面发射光电器件，如 LED 或激光器。该研究针对完全假晶的 AlAs/GaAs 异质结构进行，并与块状 GaAs 进行比较。进行了尖锐（维氏）和球形尖端的纳米压痕测试，并观察到弹出事件。我们表明，在弹入载荷下，两种材料的响应相似，即异质结构和 GaAs 的弹性参数实际上相同。然而，与 GaAs 相比，异质结构的弹出事件发生在更高的负载下。这反过来表明异质结构具有更高的抗损坏性。对于这两种材料，弹入载荷取决于加载速率。讨论了弹出的可能机制。在弹塑性阶段（弹出后），异质结构表现出比 GaAs 更低的刚度和更低的硬度。压痕测试过程中异质结构中产生的表面裂纹即使在去除负载后也会继续增长。