Rattling of Oxygen Ions in a Sub-Nanometer-Sized Cage Converts Terahertz Radiation to Visible Light.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 29099586.
- Also identified by DOI 10.1021/acsnano.7b06277.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
A simple and robust approach to visualization of continuous wave terahertz (CW-THz) light would open up opportunities to couple physical phenomena that occur at fundamentally different energy scales. Here we demonstrate how nanoscale cages of Ca<sub>12</sub>Al<sub>14</sub>O<sub>33</sub> crystal enable conversion of CW-THz radiation to visible light. These crystallographic cages are partially occupied with weakly bonded oxygen ions and give rise to a narrow conduction band that can be populated with localized, yet mobile electrons. CW-THz light excites a nearly stand-alone rattling motion of the encaged oxygen species, which promotes electron transfer from them to the neighboring vacant cages. When the power of CW-THz light reaches tens of watts, the coupling between forced rattling in the confined space, electronic excitation and ionization of oxygen species, and corresponding recombination processes result in emission of bright visible light.