In the present study, lanthanum oxytellurate (LOT) samples with varying La : Te ratios are successfully synthesized using a simple hydrothermal method that has enormous advantages. The prepared samples crystallize in a La₂O₆Te composite phase with an orthorhombic crystal system. A nanorod-like morphology is observed for each sample, and the presence of constituent elements is verified from EDX results. Chemical compositions and their oxidation states are obtained from XPS studies. Optical studies of the materials demonstrated band gap values between 2.65 and 2.78 eV, confirming the LOT samples’ semiconducting nature. Broad photoluminescence (PL) spectra with peaks ranging between 650 and 750 nm were observed, and a red shift occurred by increasing the Te concentration in the samples. Overall, the samples exhibit good photoresponse characteristics under dark and light conditions with high I_on/I_off ratios and sensitivity values. These parameters confirm the potential of LOT materials to stand out as an alternative for susceptible and effective photodetector devices. Among the samples, LOT-2 showed 10.64 μA W⁻¹ responsivity, 5.8 × 10⁷ Jones of detectivity, and a rise and fall time of 16.25 and 23.13 s, respectively, which was the best photodetection performance compared to the other two samples. Results from the nonlinear optical (NLO) Z-scan study demonstrated the RSA behavior and valley-peak configuration with positive n₂ values corresponding to the self-focusing effect. The NLO characteristics of the materials are governed by the two-photon absorption (2PA) mechanism. Here, the LOT-2 sample displayed comparatively better results than the other two. The third-order nonlinear optical NLO susceptibility χ⁽³⁾ values suggest that LOT materials have the potential to become a new candidate for various NLO applications in the coming days.

中文翻译：

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用于可见光光探测的水热合成 La2O6Te 纳米棒中的增强双光子吸收


在本研究中，使用一种具有巨大优势的简单水热方法成功合成了具有不同 La ：Te 比率的碲氧镧 （LOT） 样品。制备的样品在具有斜方晶系的 La₂O₆Te 复合相中结晶。观察到每个样品的纳米棒状形态，并从 EDX 结果中验证组成元素的存在。化学成分及其氧化态从 XPS 研究中获得。对材料的光学研究表明，带隙值在 2.65 到 2.78 eV 之间，证实了 LOT 样品的半导体性质。观察到峰范围在 650 和 750 nm 之间的宽光致发光 （PL） 光谱，并且通过增加样品中的 Te 浓度而发生红移。总体而言，样品在黑暗和光照条件下表现出良好的光响应特性，具有高 I_开/I_关比率和灵敏度值。这些参数证实了 LOT 材料作为敏感和有效光电探测器设备的替代品的潜力。在样品中，LOT-2 显示出 10.64 μA ^W-1 的响应度，5.8 × 10⁷ Jones 的检测率，上升和下降时间分别为 16.25 和 23.13 s，与其他两个样品相比，这是最好的光检测性能。非线性光学 （NLO） Z 扫描研究的结果表明 RSA 行为和谷峰值配置，正 n₂ 值对应于自聚焦效应。 材料的 NLO 特性受双光子吸收 （2PA） 机制控制。在这里，LOT-2 样品显示出比其他两个样品更好的结果。三阶非线性光学 NLO 磁化率 χ^（3） 值表明 LOT 材料有可能在未来几天成为各种 NLO 应用的新候选者。