The progress of single-band upconversion nanomaterials

Abstract

Upconversion (UC) nanomaterials (NMs) with single-band emission properties provoke widespread interest in the bio-medical field due to their advantages over those with multi-band emissions such as for high resolution in situ multiplexed molecular mapping. Several methods have been applied in recent years to realize single-band emission with different colors. In this feature article, for the first time, we provide an overview of the recent progresses in realizing single-band UC emission through different methods and the related mechanisms. Three types of strategies, including choosing an appropriate matrix, a doping ion with suitable energy level and a coating organic dye with a certain absorption wavelength, are discussed in detail. Finally, the challenges and future perspectives for these novel NMs with single-band UC emission are stated.