Fabrication and photoluminescence of Eu-doped KNN-based transparent ceramics

Outstanding optical temperature sensitivity and dual‐mode temperature‐dependent photoluminescence in Ho3+‐doped (K,Na)NbO3–SrTiO3 transparent ceramics

“…When light passes through a ceramic, the total energy of the incident light is ultimately consumed by electron transition, light transmission, and scattering. Large E g value is beneficial to reducing the energy consumed by charge carrier transitions and increasing the energy of light transmission, resulting in relatively small light loss and high optical transmittance . Therefore, the ceramics with larger E g ( x = 0.005) exhibit relatively higher transmittance (Figure A).…”

“…Although PLZT transparent ceramics have been applied in a variety of optoelectronic devices, high content of lead (>60%) is adverse for both environment and human health . Recently, (K 0.5 Na 0.5 )NbO 3 (KNN) based ceramics have been subjected to comprehensive studies as a very promising lead‐free ferroelectric material to substitute for toxic lead‐based materials due to their good piezo‐/ferro‐/pyroelectric properties, low sintering temperature, and high Curie temperature ( T c ) . It is known that pure KNN possesses orthorhombic phase and can hardly be fabricated into transparent ceramics by traditional ways.…”

“…Luminescent ferroelectrics, a novel class of multifunctional materials via doping rare‐earth ions (RE 3+ ) in soft ferroelectrics, have been envisaged for new applications in three‐dimensional displays, optical data storage, fluorescent temperature sensors, biological assaying, and medical imaging . Among them, RE 3+ ‐doped KNN‐based transparent ceramics are distinctive for relatively high mechanical strength, efficient photoluminescence (PL) performance, cost effective, and easy‐modulated optoelectronic feature . As one of the frequently studied RE 3+ , Ho 3+ has attracted considerable attention since lasing action has been demonstrated for the green up‐conversion emission (from 5 F 4 / 5 S 2 → 5 I 8 transitions) of Ho 3+ ‐doped materials .…”

Lead‐free (K,Na)NbO3‐based ceramics with high optical transparency and large energy storage ability

“…However, almost all the KNN‐based ferroelectric ceramics examined in previous studies do not satisfy the requirement of both high optical transmittance and high energy storage density. Tables and show the visible optical transparency and energy storage density of most KNN‐based ceramics studied during the 2014‐2017 time period . It was found that transparent ferroelectric ceramics with high energy storage densities have rarely been created in previous studies.…”

“…Tables 1 and 2 show the visible optical transparency and energy storage density of most KNNbased ceramics studied during the 2014-2017 time period. [12][13][14][15][16][17][18][19][20][21][22] It was found that transparent ferroelectric ceramics with high energy storage densities have rarely been created in previous studies. To achieve a high optical transparency, a material needs to have high density, low porosity, no impurities, a small grain size, and a symmetrical crystal structure are needed to eliminate all possible light scattering.…”