Phosphorescent matrix-impurity crystals

Persistent room-temperature phosphorescence (RTP) is a unique solid-state photophysical process consisting in an afterglow from an excited triplet state with ultra-long emission lifetime. RTP crystals have a wide range of applications from arts and bioimaging to optoelectronic devices. Over the past years, organic materials have emerged as promising candidates to replace inorganic and organometallic systems as RTP emitters owing to their inherent advantages (low cost and toxicity) and versatility in the tuning of their exciton properties by molecular design. Nevertheless, the persistent RTP mechanism in organic materials and underlying photophysical processes remain ambiguously described. The STAR project aims to decipher the RTP mechanism intricacies by exploring an original design in which RTP is promoted by structural impurities present in organic crystals via matrix-impurity interactions. This will be achieved by combining a variety of quantum chemistry methods, from electronic structure calculations to non-adiabatic molecular dynamics, and relying on state-of-the-art and original modelling approaches to unravel the key elementary processes and mechanistic details of RTP in these systems. The structure-properties relationships established will guide the design of new phosphors exploiting the matrix-impurity concept, and pave the way for the development of new efficient RTP systems for potential commercial use. Besides, STAR comprises an extensive agenda to disseminate results through the scientific community and engage the non-specialist public. Conducting STAR is expected to ultimately provide the researcher with the tools for reaching a stage of professional maturity and independence by i) broadening her scientific and technical background as well as her collaboration network, ii) developing her project managing and mentoring skills and, iii) boosting her track record of publications and conference contributions.