Long-persistent luminescence is a unique photophysical phenomenon, which generally exists in inorganic materials. The inorganic long-persistent luminescence materials have been widely applied in the fields of luminescence lighting and biological imaging. Compared with inorganic long-persistent luminescence materials, organic long-persistent luminescence (OLPL) materials pose attractive application prospects in many high-tech fields such as bio-imaging, optical recording, information storage and anti-counterfeiting systems due to their low price, simple synthesis, good bio-compatibility and easy modification of functional groups. However, since purely organic long-persistent luminescence phenomena can usually be observed only under harsh conditions such as very low temperature and oxygen-free environment, it is a great challenge to achieve efficient purely organic long-persistent luminescence emission at room temperature and in atmospheric environment.

Recently, Desissa Yadeta Muleta from Ethiopia, a doctor candidate of Prof. Hu Wenping’s team at the School of Science of TJU, has found purely organic long-persistent luminescence (OLPL) materials that cannot be affected in aqueous solution or in air. The stable LPL performance of this crystalline material is visible for over 8 seconds and can be maintained for at least three months even in aqueous solution or in air. These excellent properties were mainly due to the persistent RTP, attributed to the rich triplet states of both MDPA and DDF2o modules, whether in aqueous solution or in air. The research results were published in Journal of Materials Chemistry C, a high-level journal of materials science, and pose great application prospects, especially in the fields of information processing and bio-imaging technology.

According to Desissa, this crystalline material has been implemented using green screen-printing technology in air to generate a patterned bookmark, providing a great commercial prospect for anti-counterfeiting.

By Deng Qi

Editor: Eva Yin