Deep‐red‐emitting SrLaLiTeO₆: Mn⁴⁺ double perovskites: Correlation between Mn⁴⁺‐O²⁻ bonding and photoluminescence

Abstract

Among the different categories of ceramic compounds, perovskites draw worldwide attention amidst researchers due to their interesting properties such as superconductivity, nonlinear optical properties, photoluminescence, ionic conductivity, ferroelectricity, magnetoresistance, catalytic properties, etc. These versatilities in physical properties lead to the emergence of various functional electronic and optoelectronic devices that are capable of doing much better performance than their predecessors. 1 Due to hundreds of functional halide double perovskites reported over the past few years, the definition of perovskites seems inadequate and hence Song et al. categorize perovskites into three groups based on their structure viz., standard-perovskite (having 3D structure and general formula ABX 3 ), low-dimensional (low-D including 2D, 1D, and 0D) perovskites, and perovskite-like halides. 2 The first two consist of corner sharing or discrete octahedra, whereas the latter consist of edge sharing as well as face sharing octahedra. 2 The possibility of substituting cations in either A site or B site of the basic perovskite structure (ABX 3 ) leads to the formation of complex perovskites or generally double perovskites and falls under the category of "standard perovskite." The modifiability in cationic sites induces the development of new functional materials which further enhance the device properties. 1,2 Luminescence in double perovskites is an irresistible area of research and there are plenty of research articles published every year regarding this intriguing physical property. It has substantial applications in the field of photovoltaic devices, photocatalysis, electronic devices such as capacitors, transducers, sensors, lighting devices, etc. 3-8 Among these,

An Al3+-incorporated Ca2LuNbO6:Mn4+ oxide phosphor with dramatic deep-red and far-red emission bands

“…The experimental data were linearly fitted with a slope of −0.306, suggesting an activation energy of 0.306 eV. The Δ E value is larger than those of NaMgGdTeO 6 :Mn 4+ phosphor (0.253 eV), 46 Sr 2 MgGe 2 O 7 :Mn 4+ phosphor (0.24 eV), 47 SrLaLiTeO 6 :Mn 4+ phosphor (0.23 eV), 48 and Ca 14 Al 10 Zn 6 O 35 :Mn 4+ (0.183 eV), 45 indicating that the CLN 0.6 A 0.4 :0.3%Mn 4+ phosphor exhibits better thermal stability, and the possibility of thermal quenching is smaller.…”

Combustion derived single phase Y4Al2O9:Tb3+ nanophosphor: crystal chemistry and optical analysis for solid state lighting applications

“…For the estimation of the critical distance ( R c ), Blasse relation was used which is given by eqn (7) (ref. 60)Where, x C refers the critical concentration of Tb 3+ ions, V denotes cell volume and Z stands for a number of cations in a single unit-cell. For optimized sample, volume = 828.72 Å 3 and Z = 4 and the calculated R C value is 23.63 Å which validates that energy transfer takes place via multipolar interactions.…”

Designing dual-emission phosphors for temperature warning indication and dual-mode luminescence thermometry

“…By fitting with the Gaussian function, the excitation spectrum can be classified into four peaks located at 311 nm (O 2− → Mn 4+ charge-transfer band), 338 nm ( 4 A 2g → 4 T 1g ), 398 nm ( 4 A 2g → 2 T 2g ), and 473 nm ( 4 A 2g → 4 T 2g ). To study the crystal field strength of Mn 4+ ions, the crystal field strength can be calculated by the transition energy gap ( 4 A 2g → 4 T 2g ) using eqn (1), as follows: 38 D q = E ( 4 A 2g → 4 T 2g )…”