Rapid thermal annealing induced engineering of surface and photoluminescence properties of (K,Na)NbO3 thin films for optoelectronic applications

Influence of 120 MeV Au Ion Irradiation on Phase Transition, Surface, and Optical Properties of Lead‐Free (K,Na)NbO3 Films

“…These results can be correlated with the crystallinity of KNN films where the optical band gap is found to increase with a decrease in crystallinity (present case), and a reduction behavior is observed with an increase in the crystalline quality of KNN films. [29,51] Further, to support the results, Urbach energy is calculated for pristine and irradiated KNN films to study the structural disorder/defects. The origin of Urbach tail in materials is associated with structural disorders, grain boundaries, and defects (especially oxygen vacancies), which are difficult to avoid during the growth process of ferroelectric perovskites.…”

“…[49] XPS results of K 2p and Na 1s profiles of this study are in good agreement with earlier reports in the literature. [50,51] Interestingly, a slight increase in the peak intensity of Na 1s can be seen in Figure 3c. This behavior might be due to the freezing of some Na content near the surface region upon ion irradiation at higher fluence because both the alkali species are volatile.…”

“…[59,60] Moreover, the different shoulders that appeared in the PL spectra of the KNN system are owing to structural order-disorder engaged in alkali loss-induced tilting/distortion of NbO 6 octahedra, as explained in the previous report. [51] The energy transfer to target atoms leads to a rise in local amorphization/heating, which probably increases defect centers in KNN. Therefore, a high S e value may break /or weaken the oxygen bond strength, which might have resulted in oxygen vacancies and/or distortion in the NbO 6 octahedron.…”

“…These results can be correlated with the crystallinity of KNN films where the optical band gap is found to increase with a decrease in crystallinity (present case), and a reduction behavior is observed with an increase in the crystalline quality of KNN films. [ 29,51 ]…”

Understanding Crystal Spatial Symmetry of Sm/Mg Heterovalent‐Doped BST–BNT Ceramics: An Effect Mechanism for Electrical Properties

“…This phenomenon increases the interface state density and generates an asymmetric interface barrier in the ceramics resulting in a relatively large sample leakage current. [26][27][28][29] Based on the analysis depicted by XRD, the ceramic is mainly a perovskite-type tetragonal phase structure. Hence, the BST-BNT: x(Sm, Mg) ceramic piezoelectric effect is generated by the domain wall movement of 90°.…”