Donor–Acceptor Structure Induced Long-Persistent Luminescence and Application in Temperature Measurement at Cryogenic Environment

Abstract

With the development and application of cryogenic technology, the demand for temperature measurement in cryogenic environment is increasing. Optical sensing can provide a non-contact method of temperature measurement in cryogenic environments. Herein, a new temperature measurement route based on the persistent luminescence is proposed. The single-component, coordination crystal Zn-ddcphpy with electron donor and acceptor structures, achieving persistent luminescence (6–7 s) after irradiating by ultraviolet light source at 80 K. The persistent luminescence decay and electron paramagnetic resonance show that the reason for the persistent luminescence generation is the photogenerated charge separation and recombination. In cryogenic environment controlled by liquid nitrogen (80–260 K), the persistent luminescence duration decreases with increasing temperature, the color gradually changes from green to yellow with the spectrum red-shift. Taking Zn-ddcphpy as a model material, the unquiet temperature sensitive based persistent luminescence shows convenience, intuitive and inexpensive. Furthermore, the LPL (long-persistent luminescence) of Zn-ddcphpy exhibits high sensitivity and responsiveness to temperature at cryonic environment, make it suitable for temperature measurement on real time. In this work, the change of duration and color can indicate temperature without contact, which can be used for temperature measurement and monitoring in the fields of cryogenic wind tunnels, cold chain storage, etc.