Since the discovery of an effective role for defects in improving the performance of ceramic materials in practical application, investigation of defects and their impact on the development of optical properties in condensed matter physics have received widespread attention. In this work we synthesized a lead free (Ba_0·60Sr_0.40)_(1-x)(Bi,Li)_xTiO₃ (BST6:BLx%); (0%≤x ≤ 8%) ceramics using a conventional solid-state reaction method. X-ray diffraction patterns along with Rietveld refinement, Micro-Raman (MR) spectroscopy, X-ray Photoelectron Spectroscopy (XPS), UV–visible, Electron Spin Resonance (ESR) and photoluminescence (PL) measurements are utilized to characterize these ceramics. XRD, and Raman analysis have proven cubic phase symmetry with a contraction in bond length as the Bi and Li concentrations increased. XPS and ESR results confirm the presence of Ti³⁺ surface defects (TSD) and oxygen vacancies (VO) on the co-substituted samples sintered at high temperature. The optical results show a decrease in the bandgap energy from 3.14 eV to 2.76 eV and a wide-PL band emission on the green band, caused by recombination of the radiative free electrons and holes trapped around the surface oxygen vacancies. Defect levels created within the bandgap might act as recombination centres, and this can give the possibility of using BST6:BLx as a green light emission source in future practical applications.

自从在实际应用中发现缺陷在提高陶瓷材料性能方面的有效作用以来，缺陷的研究及其对凝聚态物理光学性能发展的影响受到了广泛的关注。在这项工作中，我们合成了无铅 (Ba _{0 · 60} Sr _0.40 ) _(1-x) (Bi,Li) _x TiO ₃(BST6:BLx%); (0%≤x≤8%) 陶瓷使用传统的固态反应方法。X 射线衍射图与 Rietveld 精修、微拉曼 (MR) 光谱、X 射线光电子能谱 (XPS)、紫外-可见光、电子自旋共振 (ESR) 和光致发光 (PL) 测量一起用于表征这些陶瓷。XRD 和拉曼分析已经证明了立方相对称性，随着 Bi 和 Li 浓度的增加，键长收缩。XPS 和 ESR 结果证实了 Ti ³⁺的存在高温烧结的共取代样品上的表面缺陷（TSD）和氧空位（VO）。光学结果显示带隙能量从 3.14 eV 降低到 2.76 eV，绿带上出现宽 PL 带发射，这是由于在表面氧空位周围捕获的辐射自由电子和空穴的复合引起的。在带隙内产生的缺陷水平可能充当复合中心，这可以为在未来的实际应用中使用 BST6:BLx 作为绿光发射源提供可能性。