Nanocrystalline SnO₂ thin film was, successfully, synthetized by using USP method. The structural and optical properties of SnO₂ nanocrystallites were studied by using XRD, AFM, UV–Vis-NIR and PL spectroscopies. The XRD pattern confirmed the tetragonal rutile structure of SnO₂ nanocrystallites with average crystalline grain size of 41 nm. AFM images show a dense surface of columnar grains with RMS surface roughness of 8.87 nm. UV–Vis-NIR measurements exposed a direct band gap of energy 3.58 eV. The PL spectrum recorded at 7 K reveals the presence of PL peaks centered in IR and Vis regions, attributed to radiative transitions via oxygen vacancies, Sn interstitials and dangling bonds. A schematic bands diagram is proposed with the approximate positions of intrinsic point defect levels in nanocrystalline SnO₂ thin films. The integrated PL measurements demonstrate the good thermal stability of our sample. The unusual behavior of PL peaks and their FWHM evolution as a function of temperature indicates the thermal sensitivity of the intrinsic point defects energy levels present in band gap. Indeed, the shallower energy levels due to dangling bonds and/or oxygen vacancies are more sensitive to the temperature. However, the volume defects like Sn interstitials are thermally stable and constitute deep and stable energy levels for photoexcited electrons. Small redshifing of PL peaks is observed with the increasing of temperature. This is attributed to the reduction of oxygen vacancies.

采用USP方法成功合成了纳米晶SnO _2薄膜。利用 XRD、AFM、UV-Vis-NIR 和 PL 光谱研究了SnO ₂纳米晶的结构和光学性质。XRD图谱证实了SnO ₂纳米微晶的四方金红石结构，平均晶粒尺寸为41 nm。AFM 图像显示出致密的柱状晶表面，RMS 表面粗糙度为 8.87 nm。UV-Vis-NIR 测量暴露出能量为 3.58 eV 的直接带隙。在 7 K 处记录的 PL 光谱显示，存在以 IR 和 Vis 区域为中心的 PL 峰，这归因于通过氧空位、Sn 间隙和悬空键的辐射跃迁。_{提出了一个示意性的能带图，其中给出了纳米晶SnO 2}薄膜中本征点缺陷能级的大致位置。集成的 PL 测量表明我们的样品具有良好的热稳定性。PL 峰的异常行为及其作为温度函数的 FWHM 演变表明带隙中存在的本征点缺陷能级的热敏感性。事实上，由于悬空键和/或氧空位而导致的较浅能级对温度更敏感。然而，像Sn间隙原子这样的体积缺陷是热稳定的，并且为光生电子构成深而稳定的能级。随着温度的升高，观察到 PL 峰出现小红移。这归因于氧空位的减少。