Ternary-Host and Heterojunction Enabled Eye-Visible Elastic Mechanoluminescence from (Ca_0.5Sr_0.5)ZnOS/xZnS/Mn²⁺

Abstract

Mechanoluminescence (ML) is one kind of mechanical-tooptical energy conversion, and a strategy toward achieving bright elastic ML emission is strongly anticipated for ML application. Herein, a ternary-host strategy is proposed for synthesizing heterojunction ML materials with eyevisible elastic ML under an ultralow pressure of 2 N, in which ZnS, CaCO 3 , and SrCO 3 are employed as precursors to prepare the ternary-host (Ca 0.5 Sr 0.5 )-ZnOS/xZnS. Upon partially substituting the precursor ZnS with MnCO 3 , the Mn 2+ activator could introduce luminescent centers and carrier traps into the ternary-host (Ca 0.5 Sr 0.5 )ZnOS/xZnS and enable achieving a series of (Ca 0.5 Sr 0.5 )ZnOS/xZnS/Mn 2+ phosphors with bright and pressure-sensitive elastic ML. The (Ca 0.5 Sr 0.5 )ZnOS/xZnS/Mn 2+ phosphors not only exhibit eyevisible red ML under ambient conditions without any preirradiation but can also display a linearly enhanced ML intensity along with the enlarged external force at a 2 N interval as well as regeneratable ML upon repetitively applying an external force 20 times. The maximum emission wavelength of ML can be conveniently modulated from 623 to 658 nm by adjusting the ZnS content of (Ca 0.5 Sr 0.5 )ZnOS/xZnS/Mn 2+ phosphors.

Alkaline-earth-metal-ion blending enhanced mechanoluminescence of lanthanide ions in MZnOS hosts for stress sensing and anticounterfeiting

“…[14][15][16][17][18] Owing to the simplified synthetic method, 19 convenient post-processing steps and long-term storage stability of inorganic-crystal ML hosts compared to the organic-complex ML hosts, 1,12 inorganic-crystal ML hosts are being extensively explored and utilized to design novel ML materials, 20,21 such as oxonitridosilicates BaSi 2 O 2 N 2 , 22 niobates (Li, Na)NbO 3 , 15 (Ca, Sr) 2 Nb 2 O 7 , 23 aluminate SrAl 2 O 4 24, 25 and quaternary oxysulfides (MZnOS, M = Ca, Sr, and Ba). [26][27][28][29][30] MZnOS is an important kind of host to design ML materials, [31][32][33] because flexible ML emission can be conveniently achieved via partially replacing the M 2+ (M = Ca, Sr, and Ba) sites of the MZnOS host with different dopant ions, such as transition metal ions [33][34][35][36][37][38][39] and lanthanide ions. 27,40,41 Benefitting from the rich energy level property of lanthanide ions, 42 doping MZnOS with lanthanide ion-dopants is being frequently employed to achieve multi-waveband ML.…”

“…MZnOS is an important kind of host to design ML materials, 31–33 because flexible ML emission can be conveniently achieved via partially replacing the M 2+ (M = Ca, Sr, and Ba) sites of the MZnOS host with different dopant ions, such as transition metal ions 33–39 and lanthanide ions. 27,40,41 Benefitting from the rich energy level property of lanthanide ions, 42 doping MZnOS with lanthanide ion-dopants is being frequently employed to achieve multi-waveband ML.…”