About this Research Topic
The many unique optical characteristics of lanthanide ions (Ln3+), including sharp intra 4f→4f transitions, long excited state lifetimes, large Stokes shift and enhanced color purity have led to a great surge in the development of a plethora of Ln3+-doped luminescent nanomaterials. In addition to simple Stokes shifted emission, some Ln3+ ions have the ability to convert low energy photons into high energy emission photons via the upconversion process. This nonlinear upconverting property is highly efficient in Ln3+-doped materials and has widened the application scope of these materials from traditional phosphors to excellent optical probes for efficient deep tissue imaging, temperature sensing, security inks, and more. In addition, the spatial and temporal energy transfer features of Ln3+ ions provide an efficient method to alter and tune the optical properties of other materials and further broadening their potential.
Despite these excellent optical characteristics and the volume of research on Ln3+-doped nanocrystals, there is still huge scope for improvement and a number of challenges to address. For instance, the low absorption co-efficient of many Ln3+ ions demands the development of new and efficient sensitizers for multi-fold enhancement in their luminescent intensities. Synthetic methods to make these colloidal nanocrystals still mandate the need for high temperature or high pressure. Any sustainable synthetic strategy using low temperatures without compromising the optical properties is undoubtedly a boon. In addition, Ln3+ ions exhibit rich optical transitions in the near infrared (NIR) region which have been less explored for different applications. Development of new host matrices or hybrid materials, particularly using semiconductors, would allow electrical excitation in addition to photo-excitation of these nanocrystals, which is expected to greatly widen their scope of possible applications. The objective of this Research Topic on Ln3+-doped luminescent nanomaterials is to publish quality research articles in this field and to disseminate the potential applications of these versatile nanomaterials in a diverse range of research areas.
We welcome insightful research articles and mini-reviews covering fundamental understanding of the synthesis, spectroscopy, and applications of these materials. Potential themes include, but are not limited to:
• Novel synthetic methodologies
• Development of new host matrices such as perovskites
• Spectroscopic investigations
• Synthesis and photophysical studies of novel Ln3+-doped nanocomposites
• Rational design of nanocrystals/composites for specific applications including detection, temperature sensing, drug delivery, bio-imaging, solar cells, security inks and photocatalysis
Keywords: lanthanides, upconversion, sensing, energy transfer, bio-imaging
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.