Strengthening the non-pre-irradiated near-infrared mechanoluminescence of CaZnOS:Nd³⁺ by Mn²⁺ coactivation for biomechanical imaging

Abstract

The development of lanthanide-activated CaZnOS mechanoluminescent (ML) phosphors that can produce non-pre-irradiated mechanoluminescence (ML) in the near-infrared (NIR) region opens a new avenue for in vivo and in situ biomechanical...

Unraveling Mechanoluminescent Mechanisms in Doped CaZnOS Materials: Co‐Mediation of Trap‐Controlled and Non‐Trap‐Controlled Processes

“…We speculated that the weak ML in CaZnOS:Er 3+ originated from the small absorption cross‐sectional area and parity‐forbidden 4f–4f transition of Er 3+ . [ 16 ] The weakest ML in CaZnOS:Ce 3+ may be attributed to the generation of Ce 4+ (Figure S10, Supporting Information), which is typically known to suppress luminescence. [ 43,44 ] Third, the contribution of trap‐controlled ML was much higher than that of non‐trap‐controlled ML (Figure S3, Supporting Information), ranging from 68.46% to 99.72% versus 0.28% to 31.54%, independent of the wavelength regions and the types and conditions of mechanical stimulation (Figure 12c,f).…”

“…[ 1 − 9 ] Among the various ML materials developed, CaZnOS‐based materials stand out due to their unique capability to host diverse luminescent centers, enabling tunable ML spectra across the ultraviolet–visible–near infrared (UV–vis–NIR) range. [ 2,10,11 ] This versatility has demonstrated potential in colorful ML displays/sensors, [ 12 − 14 ] biomechanical imaging, [ 15,16 ] and biomedical light sources. [ 17,18 ] However, the reported ML properties and mechanistic interpretation of CaZnOS‐based materials are highly contradictory, impeding their further development and utilization.…”