Persistent Luminescence in Comparison to Phosphorescence

Persistent luminescent (PersLumin) materials are extremely attractive for energy-efficient applications due to their exceptional ability for temporary storage and gradual release of light. Persistent luminescence is a fascinating optical phenomenon in which light can persist at room temperature after the UV–vis irradiation source has been removed. Thermally driven recombination of charge carriers trapped at host intrinsic defect locations produces such phosphorescence decay. It is nevertheless essential to throw some light on the basic terminology such as persistent luminescence and phosphorescence. For the economic development and rapid rise in global energy demand, the investigation of unconventional renewable energy sources is critical. Over the past few years, mechanistic studies appear to have matured due to the great efforts of researchers. This has aided in the development of novel materials for applications in areas like in vivo bioimaging, security signs, emergency lighting, interior decorating, AC-LEDs and optical storage media. The innovative use of LED lighting powered by renewable energy can have a positive impact on the environment by reducing greenhouse gas emissions and less deforestation, as well as providing people with a more affordable source of lighting. This chapter highlights the key differences between phosphorescence and PersLumin materials including their history. The chapter also includes a summary of the present-day status, trends in research of PersLumin materials and their practical applications nowadays. In the subsequent sections, the earlier as well as advanced PersLumin mechanisms are divided into various models, mainly the electron trapping–detrapping and hole trapping-detrapping models. Furthermore, the advancement made in this field through valuable research inputs such as bandgap engineering is discussed in detail. Moreover, we cover phosphorescence and PersLumin in both inorganic and organic phosphor materials. Besides, we highlight the upcoming potential, targets and challenges (like under trial bioimaging technique) and probable solutions to these challenges.