None‐rare‐earth activated Ca₁₄Al₁₀Zn₆O₃₅:Bi³⁺,Mn⁴⁺ phosphor involving dual luminescent centers for temperature sensing

Abstract

We proposed a new strategy for utilizing rare‐earth–free‐activated self‐referencing optical material with dual activators for temperature sensing, which was synthesized by conventional high‐temperature solid‐state method and was scarcely reported. Originating from the different thermal responses of Mn4+ and Bi3+ ions, a Mn4+/Bi3+‐based dual‐emitting fluorescence intensity ratio (FIR) as dual‐modal temperature signal for temperature sensing has been corroborated as a promising temperature sensing method. Due to the outstanding thermal resistance of activator Mn4+ (anti‐Stokes) benefiting from the unique 3dn electronic configurations and strong field strength of host, together with the energy transfer from Bi3+ to Mn4+ ions and excellent thermal quenching of Bi3+, this temperature‐sensitive phosphor displayed both an extensive detection temperature region ranging from 303 to 563 K and excellent absolute and relative sensitivity of 0.0147 K−1 and 1.21% K−1 respectively, both of which are higher than some foregoing reported optical materials. Furthermore, two well‐separated emission peaks at blue and red regions enabled an excellent signal discriminability and accurate temperature detection under the single‐wavelength excitation of 340 nm. In addition, freedom from rare‐earth ions contributed its possibility to be mass‐produced for meeting the needs of economic rationality, nontoxic and convenient synthesis. It is anticipated that this preliminary study would arouse peoples’ attention on exploring more novel dual activator‐based optical thermometric materials in absence of rare‐earth ions.

Intensity enhancement of photoluminescence in Tb3+/Eu3+ co‐doped Ca14Zn6Al10O35 phosphor for WLEDs

“…[1] The rare-earth (RE) elements which show luminescence properties have been extensively used in many displays, lasers, lighting, anti-counterfeiting applications, biosensors, fibre amplifiers, optical thermometry, etc. [2][3][4][5][6] At present, white light emitting diodes (WLEDs) have become the conventional lighting source in different fields because of their advantages. [7][8][9][10][11][12][13] However, the performance of the available green and blue emitting phosphors is substantially higher than that of the currently utilized Y 2 O 2 S:Eu 3+ red phosphor.…”

Fundamental luminescence properties of Mn4+ activated Ca14Al10Zn6O35 phosphor

“…For example, the broad and intense excitation band of Mn 4+ and the efficient Mn 4+ -Ln 3+ (Ln = Nd, Yb, Er, and Tm) energy transfer ensures the convenient realization of strong nearinfrared emission, [28][29][30][31] while the co-doping of Bi 3+ /Dy 3+ can tune the emission from deep-red to white/yellow/blue. [32][33][34][35][36] Based on these studies, CAZO:Mn 4+ and its analogues have been regarded as promising luminescent materials for application in white LEDs, indoor agriculture, solar cells, ratiometric optical thermometers, and infrared devices for laser and biochemical detection.…”

A review on the structural dependent optical properties and energy transfer of Mn4+ and multiple ion-codoped complex oxide phosphors

“…To maintain the electroneutrality of the compound, excess metal ion vacancies and O 2À ions in the lattices of complex oxides may be formed for charge compensation. [25][26][27][28][29][30] The upconverted NIR luminescence of Mn 4+ was realized with the aid of the efficient energy transfer of Yb 3+ / Ln 3+ / Mn 4+ in the specially prepared Yb 3+ /Ln 3+ /Mn 4+ (Ln ¼ Er, Ho, Tm) codoped YAlO 3 and its energy transfer efficiency was systematically claried by its steady-state and time-resolved upconverted emission spectra. 31 The dual emission based on Mn 4+ and multiple ion (such as Yb 3+ , Ln 3+ , and Mn 4+ ) codoped phosphors is promising for accurate temperature sensors due to the fact that the thermal quenching mechanisms of Mn 4+ and Ln 3+ are different.…”