Manipulating the photoresponse of two-dimensional electron gas at the interface of complex oxides is attracting tremendous interest because of its potential applications in photoelectric devices. In this study, transport behaviors of LaAlO3/SrTiO3 heterointerfaces tuned by a nickelate buffer layer under light irradiation have been investigated. With the increasing thickness of the buffer layer, the LaAlO3/SrTiO3 interfaces exhibit the metal-to-insulator transition. More importantly, we also observe a substantial enhancement in the photoresponse under a 360 nm light irradiation and the relative change in the resistance of heterointerfaces is enhanced from 6.8% (without a buffer layer) to 50 139% (with a 1.6 u.c. buffer layer) at 300 K. Moreover, the heterointerfaces exhibit a state of change from persistent to transient photoconductivity. These emerging results are analyzed in view of the relevant mechanisms of band bending and lattice effects. This work provides experimental support for the application of perovskite oxides in interface optoelectronics.

中文翻译：

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镍酸盐缓冲层在 LaAlO3/SrTiO3 界面处的巨大增强光响应

由于其在光电器件中的潜在应用，在复合氧化物界面处操纵二维电子气的光响应引起了极大的兴趣。在这项研究中，研究了在光照射下由镍酸盐缓冲层调节的 LaAlO3/SrTiO3 异质界面的传输行为。随着缓冲层厚度的增加，LaAlO3/SrTiO3 界面呈现金属到绝缘体的转变。更重要的是，我们还观察到在 360 nm 光照射下光响应的显着增强，异质界面电阻的相对变化从 6.8%（没有缓冲层）增强到 50 139%（有 1.6 uc 缓冲层）在 300 K。此外，异质界面表现出从持久到瞬态光电导的变化状态。鉴于能带弯曲和晶格效应的相关机制，对这些新出现的结果进行了分析。该工作为钙钛矿氧化物在界面光电子学中的应用提供了实验支持。