Thermally Activated Long Persistent Luminescence of Organic Inorganic Metal Halides

Long persistent luminescence (LPL) materials of SrAl2O4 doped with Eu2+ or Dy3+ can maintain emission over hours after ceasing the excitation but suffer from insolubility, high cost, and harsh preparation. Recently, organic LPL of guest-host exciplex systems has been demonstrated via an intermediate charge-separated state with flexible design but poor air-stability. Here, we synthesized a nontoxic two-dimensional organic-inorganic metal hybrid halides (OIMHs), called PBA(2)[ZnX4] with X=Br or Cl and PBA=4-phenylbenzylamine. These materials exhibit stable LPL emission over minutes at room-temperature, which is two orders of magnitude longer than those of previously reported OIMHs. The mechanism study shows that the LPL emission comes from thermally activated charge separation state rather than room-temperature phosphorescence. Moreover, the LPL of PBA(2)[ZnX4] can be excited by low power sources, representing an effective strategy for developing low-cost and high-stability LPL systems.

Automated summary

Recently, researchers synthesized a nontoxic two-dimensional organic-inorganic metal hybrid halides (OIMHs) called PBA(2)[ZnX4], which exhibit stable long persistent luminescence (LPL) emission at room temperature and can be excited by low power sources. The LPL emission comes from the thermally activated charge separation state, and these materials have low cost and high stability.