Predicting and achieving self-recoverable mechanoluminescence based on contact electrification

Area of Science:

• Materials Science
• Solid State Physics
• Luminescence

Background:

• Self-recoverable mechanoluminescence (ML) enables light emission under stress, crucial for intelligent devices.
• Existing self-recoverable ML is primarily linked to piezoelectric materials, limiting its scope.
• A novel approach is needed to broaden the applicability of self-recoverable ML.

Purpose of the Study:

• To explore self-recoverable ML based on contact electrification.
• To introduce and validate key parameters (ΔΦs, εs) for quantifying contact electrification in phosphors.
• To develop a general strategy for achieving self-recoverable ML in a wider range of materials.

Main Methods:

• First-principles calculations to determine surface relative work function (ΔΦs) and surface dielectric constant (εs) for 114 phosphors.
• Experimental validation using 19 commercial phosphors to correlate ML behavior with calculated parameters.
• Interface engineering applied to inactive phosphors to enhance contact electrification and induce self-recoverable ML.

Main Results:

• A strong correlation was found between self-recoverable ML and the contact electrification parameters (ΔΦs, εs).
• Phosphors with high ΔΦs and low εs exhibited active self-recoverable ML.
• Interface engineering successfully induced self-recoverable ML in previously inactive phosphors.

Conclusions:

• Contact electrification offers a viable mechanism for self-recoverable ML, distinct from piezoelectricity.
• The parameters ΔΦs and εs serve as effective predictors for self-recoverable ML capabilities.
• This work provides a general strategy for designing and developing self-recoverable ML materials for diverse applications.