Strong Upconversion Photoluminescence and Large Ferroelectric Polarization in Er³⁺–Yb³⁺–W⁶⁺ Triply Substituted Bismuth Titanate Thin Films Prepared by Chemical Solution Deposition

Abstract

Strong upconversion photoluminescence and large ferroelectric polarization were observed for the first time in layered structure Er3+–Yb3+–W6+ triply substituted bismuth titanate thin films. The thin films were prepared on fused silica and Pt(111)/Ti/SiO2/Si substrates by chemical solution deposition. Two green emission bands and a red one were observed in the upconversion photoluminescence spectra for all the films pumped by a 980 nm laser diode, which correspond to 2H11/2, 4S3/2, and 4F9/2 to 4I15/2 transitions of Er3+ ions, respectively. A two‐photon energy‐transfer process was confirmed by the power dependence of emission intensity. Compared with that of Er3+–Yb3+‐substituted bismuth titanate thin films, the improved photoluminescence is related to the reduced defects such as oxygen vacancies due to B‐site (Ti4+) substitution by W6+ ions, while the large ferroelectric remnant polarization can be attributed to the increased structure distortion and the reduced oxygen vacancies due to cosubstitution of A‐site (Bi3+) and B‐site (Ti4+) by Er3+, Yb3+, and W6+ ions, respectively. The combination of the strong upconversion photoluminescence and the good ferroelectric properties in the thin films would open the possibility of realizing novel multifunctional optoelectronic integration device applications.

Chemical substitution-induced exceptional emitting-wavelength tuning in transition metal Ni2+-doped ferroelectric oxides with ultrabroadband near-infrared luminescence

“…Activator Ni 2+ seems to show little effect on the ferroelectric property, which is similar to earlier reports by other researchers studying metal-ion doped ferroelectrics. 20,21 Fig. 1 NIR PL spectra of Ni 2+ -doped BST samples under 360 nm excitation are presented in Fig.…”

“…It is well known that chemical substitution is capable of tuning crystal structure and symmetry in perovskite oxides and therefore dramatically altering the materials' properties. In fact, REdoped ferroelectric oxides possessing perovskite structure have been studied by Bao et al 20,21 The simultaneous existence of ferroelectric and optical properties was observed, which may be attractive for applications in multifunctional devices. Our recent works indicate that tunable and enhanced upconversion luminescence can be realized in RE-doped ferroelectric BaTiO 3 (BTO) materials resulting from the benet of the unique crystal structure of ferroelectric perovskites.…”

The Effects of Li+ Doping on Structure and Upconversion Luminescent Properties for Bi3.46Ho0.04Yb0.5Ti3O12: xLi Phosphors

“…During the fabrication of Bi 3.46 Ho 0.04 Yb 0.5 Ti 3 O 12 : xLi phosphors, LiNO 3 (99%, Macklin, Shanghai, China), Bi(NO 3 ) 3 •5H 2 O (99%, SCRC, Shanghai, China), Ho(NO 3 ) 3 •6H 2 O (99.99%, Rknerc, Shanghai, China), Yb(NO 3 ) 3 •5H 2 O (99.99%, Rknerc, Shanghai, China) and Ti(OC 4 H 9 ) 4 (AR, Macklin, Shanghai, China) were used as the precursors of Li, Bi, Ho, Yb, and Ti ions, respectively. Ho, Yb, and Ti precursors were weighed according to stoichiometry of the formula of Bi 3.46 Ho 0.04 Yb 0.5 Ti 3 O 12 : xLi, and Bi and Li precursors exceeded 15% and 10% to supplement Bi and Li loss because both of them can partly volatilize during high-temperature treatment [20]. At first, the weighted Li, Bi, Ho, Yb precursors were put into a beaker, and then 15 mL acetic acid (AR, Macklin, Shanghai, China) was added rapidly, followed by heated under 55 • C and stirred for 15 min, and then cooled down to room temperature to obtain solution denoted as A liquid.…”

NIR to Visible Up‐conversion Luminescence of Er3+‐Doped PMN‐PT Transparent Ceramics

“…It is known that the host material plays an important role in the up‐conversion process in Er 3+ ions. Up to now many kinds of host materials have been investigated, for example, glasses, polycrystalline powders, single crystals, thin films, nano‐crystals, and transparent ceramics . However, the application is still restricted because of poor chemical stability and the low laser‐induced damage threshold of hosts …”

“…Up to now many kinds of host materials have been investigated, for example, glasses, polycrystalline powders, single crystals, thin films, nano-crys-tals, and transparent ceramics. [14][15][16][17][18][19][20] However, the application is still restricted because of poor chemical stability and the low laser-induced damage threshold of hosts. 21 Besides the excellent electrical properties, PMN-PTs are the most promising nonlinear optical materials because of the extremely high electro-optic (EO) coefficient and the strong photorefractive effect.…”