Dipolar‐Ligand‐Driven Interfacial Charge Dynamics Engineering for Enhancing Mechanoluminescence Utilization Efficiency

ABSTRACT

Mechanoluminescent materials offer unique opportunities for power‐free light‐emission systems, however, pushing mechanoluminescent performance to its intrinsic limit remains a critical challenge for reliable identification under bright ambient lighting. Here, we rationally tune dipolar ligand‐assisted interfacial charge dynamics to achieve high‐bright mechanoluminescence, and define a photoluminescence‐based mechanoluminescent utilization efficiency that quantifies the ability of traditional ZnS:Cu@AlO _x phosphors to generate photons under mechanical activation. By using a series of dipolar benzoic‐acid‐based ligands, we functionalize the outer AlO _x surface to elevate the charge potential and work function, thereby maximizing positive triboelectricity, while simultaneously suppressing non‐radiative recombination through an enhanced surface potential barrier at the inner interface. In particular, we find 4‐aminophthalic acid as an optimal dipolar ligand, which boosts the mechanoluminescent utilization efficiency from 12.7% to 76.6%, enabling clearly distinguishable luminescence even under bright ambient illumination of 110 lx. Our framework establishes a general guideline for designing, evaluating, and deploying high‐performance mechanoluminescent systems across diverse power‐free photonic and sensing applications.