Figure 1. Rational design for emission tuning in lanthanide-doped nanocrystals through cation exchange.
(a) Schematic representation of a typical cation exchange process, occurring at the particle surface, between lanthanide (Ln3+) and exchange (Xn+) ions. (b) Proposed energy management process for cation exchange-mediated luminescence tuning in the nanocrystals. The energy transfer process mainly comprises energy harvesting, energy migration and energy trapping through different types of lanthanides. DC and UC represent downconversion and upconversion processes, respectively. (c) Typical luminescent ions used for cation exchange-mediated luminescence tuning and their main emitting transitions in the ultraviolet and visible part of the electromagnetic spectrum.