Lead-free Mn²⁺-based metal halide materials are now being considered as clean candidates for backlight displays and lights due to the d–d transition, diverse components, and environmental friendliness. Therefore, efficient and stable Mn²⁺-based metal halide phosphors are in great demand for practical applications. In this work, adopting the mixed-ligand strategy, a series of [(CH₃)₄N]_2−x[(C₂H₅)₄N]_xMnCl₄ phosphors were synthesized by mechanochemical process. With the increase molar ratio of (CH₃)₄N/(C₂H₅)₄N, the phase of phosphors is transformed from orthorhombic to tetragonal. Compared to [(CH₃)₄N]₂MnCl₄ and [(C₂H₅)₄N]₂MnCl₄ phosphors, the mixed-ligand strategy significantly boosts the green emission intensity of Mn²⁺-based metal halide phosphors. The obtained [(CH₃)₄N][(C₂H₅)₄N]MnCl₄ phosphors exhibit a high photoluminescence quantum yield (PLQY) of 83.78% under 450 nm excitation, which is attributed to the modulation of the adjacent [MnCl₄]₂- distance by using the different chain length of organic cations, effectively suppressing non-radiative recombination. Additionally, the [(CH₃)₄N][(C₂H₅)₄N]MnCl₄ phosphors exhibit a green emission at 516 nm, narrow full width at half-maximum (FWHM) of 45.53 nm, and good thermal stability. The constructed white light-emitting diode (WLED) device exhibits a wide color gamut of 108.3% National Television System Committee, demonstrating the suitability of the [(CH₃)₄N][(C₂H₅)₄N]MnCl₄ phosphors as a green emitter for WLED displays and lightings. This work provides a new way to modulate the PL performance of manganese-based metal halides for application in the optoelectronic field.

Flexible PbZr_0.52Ti_0.48O₃ (PZT) films have a wide application prospect in wearable devices. In this work, PZT films were fabricated on LaNiO₃–based Si substrates and mica substrates, respectively. The effects of Si substrates and mica substrates on the dielectric and ferroelectric properties of PZT films were studied. The stability of PZT films on different substrates was discussed by controlling temperature and frequency. The optimal annealing temperature for preparing PZT films on LaNiO₃–based Si substrates and mica substrates is 750 °C. The dielectric and ferroelectric properties of PZT films vary with the substrates. The diffraction peak of PZT films deposited on mica substrates shifted to the left compared with that deposited on Si substrates, due to difference of the expansion coefficients. The as–prepared PZT films exhibit a good ferroelectric property at a frequency in the range of 100 Hz~1000 Hz. Moreover, PZT films deposited on mica substrates have larger remanent polarization values and coercive fields than PZT films deposited on Si substrates. With the elevation in temperature, the dielectric constant of PZT films gradually enhance. And as–prepared PZT films at an annealing temperature of 750 °C have a better dielectric temperature stability. PZT films grown on Si substrates exhibit more excellent dielectric temperature stability than that of PZT films grown on mica substrates.