Photodielectric and photochromic properties of (K_0.5Na_0.5)NbO₃ lead-free ceramics modified by (Ca_2/3Mg_1/3)(Zn_1/3Nb_2/3)O₃

The physical properties of ceramics stimulated by light are interesting for exploring new applications. The (Ca_2/3Mg_1/3)(Zn_1/3Nb_2/3)O₃ modified (K_0.5Na_0.5)NbO₃ ceramics (KNN-xCMZN) were designed to study the photodielectric and photochromic properties. The samples exhibited a typical perovskite structure. With an increase of the CMZN content, the phase structure transformed from the orthorhombic phase to the pseudo-cubic phase, and the grain size gradually decreased. A significant photodielectric response was observed under 365 nm light irradiation. A high dielectric tunability of up to ~ 960% was achieved at a test frequency of 80 Hz and x = 0.03. Meanwhile, a photo-induced color change of the samples was observed from white to light grey, and returned to its original state after heating at 200 °C for 5 min. Therefore, these results provided a valuable guidance for developing multifunctional optoelectronic devices.