Modulating anomalous thermal quenching behavior of stimulation luminescence via high-orbit electronic satellite-stabilized Trap state in germanate-based phosphors for 5D optical data storage

TL;DR

This paper introduces germanate-based phosphors with high-orbit electronic satellite-stabilized trap states that modulate anomalous thermal quenching in persistent luminescence, enabling advanced 5D optical data storage for high-temperature applications.

Contribution

It presents a novel design of phosphors with long-range electron traps that improve high-temperature luminescent performance and enables multi-dimensional optical data storage.

Findings

Demonstrated anomalous thermal quenching behavior in Mg2GeO4:Ti4+,Ln3+ phosphors.

Achieved high carrier retention due to Ti4+Mg2+ electron traps.

Developed 5D optical data storage system with encrypted engine for aerospace applications.

Abstract

Persistent luminescence (PersL) materials, widely used in emergency lighting and information storage, are primarily employed at room temperature. However, their luminescent performance deteriorates sharply at high temperatures. Herein, a serials of Mg2GeO4:Ti4+,Ln3+ (Ln = Tb, Eu) phosphors demonstrated anomalous thermal quenching PersL due to the temperature-dependent Fermi-Dirac distribution of bound charge carriers of Ti4+Mg2+ as remote electron traps and VMg2+ as hole traps. The high carrier retention rate of phosphors is attributed to the ability of Ti4+Mg2+ positive charge center to strongly trap non-bonding electrons over a long range (about 20 angstroms) as the electronic satellite for its stable operation. Under external optical/thermal stimulation, the released electrons and holes recombine at the different luminescent levels of Tb3+, resulting in the emission of different PersL branching ratios. Using these phosphors, we have developed 5D optical data storage (2D plane + trap depth + temperature + time) and the encrypted engine program for high-temperature aerospace engines. This study reveals the energy storage process of long-range trapping and releasing electrons by Ti4+ electron traps, and provides a new design concept for the design of PersL materials.