Rattling of Oxygen Ions in a Sub-Nanometer-Sized Cage Converts Terahertz Radiation to Visible Light

Journal Article · Tue Oct 04 00:00:00 EDT 2016 · ACS Nano

DOI:https://doi.org/10.1021/acsnano.7b06277· OSTI ID:1485325

Toda, Yoshitake  ^[1]; Ishiyama, Shintaro ^[2]; Khutoryan, Eduard ^[3]; Idehara, Toshitaka ^[4]; Matsuishi, Satoru ^[1]; Sushko, Peter V. ^[5]; Hosono, Hideo ^[1]

---

1. Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
2. Graduate School of Science and Technology, Hirosaki University, 1 Bunkyo-cho, Hirosaki-shi, Aomori-ken 036-8560, Japan; Research Center for Development of Far-Infrared Region, University of Fukui, Bunkyo 3-9-1, Fukui 910-8507, Japan
3. Institute of Radio Physics and Electronics, National Academy of Science of Ukraine, Volodymyrska 54, Kyiv, 01030, Ukraine
4. Research Center for Development of Far-Infrared Region, University of Fukui, Bunkyo 3-9-1, Fukui 910-8507, Japan
5. Physical Sciences Division, Physical &, Computational Sciences Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States

A simple and robust approach to visualization of terahertz (THz) light would open up opportunities to couple physical phenomena that occur at fundamentally different energy scales. Here we demonstrate how nanoscale cages of Ca₁₂Al₁₄O₃₃ crystal enable a novel method for conversion THz radiation to visible light. These crystallographic cages contain weakly bonded oxygen ions and give rise to a low-energy conduction band that can populated with localized yet mobile electrons. THz light excites a nearly stand-alone rattling motion of the encaged species, which promotes electron transfer from them to the neighboring cages. When the power of 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.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1485325
• Report Number(s): PNNL-SA-124011
• Journal Information: ACS Nano, Vol. 11, Issue 12; ISSN 1936-0851
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English