Photo‐Electrochemical Device Enabling Luminescence Switching of LaPO4:Ce, Tb Nanoparticle Layers. Issue 5 (23rd December 2020)

• Record Type: Journal Article
• Authors: Klein, Jonas; Beladi‐Mousavi, Seyyed Mohsen; Schleutker, Marco; Taffa, Dereje Hailu; Haase, Markus; Walder, Lorenz
• Is Part Of: Advanced optical materials. Volume 9:Issue 5(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-12-23
• Subjects: electrochemistry -- lanthanides -- logic gates -- luminescence switching -- redox mediators; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.202001891
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: The luminescence properties of LaPO4 :Ce, Tb nanoparticles are known to depend on the oxidation state of the cerium ions. However, their assembly into thin films exhibiting reasonable fast Ce 3+/4+ electrochemistry is not trivial. Herein, the electrochemical luminescence switching of LaPO4 :Ce, Tb nanoparticles, assembled as nonconducting thin films, using two electrocatalytic processes, is demonstrated. Due to the insulating nature of these nanoporous films, redox shuttles are used to access the redox active Ce 3+/4+ species for electrochemical reactions. A series of redox shuttles with various redox potentials are employed to investigate their capability to electrochemically oxidize Ce 3+ within the nanoparticles. Thereby the formal redox potential of the Ce 3+/4+ couple in LaPO4 :Ce, Tb nanoparticles is determined to lie within 0.89 and 1.15 V versus Ag/AgCl. In situ observation of repetitive luminescence switching is realized by assembling a device that allows UV light to enter the nanoparticle layer. With two redox shuttles present in the electrolyte, one for the oxidation of Ce 3+ and the other for reduction of Ce 4+, quenching and restoration of the luminescence is monitored. The resulting device represents the first down‐sizable logical AND gate with UV light and voltage inputs and a vis light output based on a solid state LaPO4 :Ce, Tb layer. Abstract : Redox reactions of cerium atoms within nonconducting LaPO4 :Ce, Tb nanoparticle thin films are electrochemically induced by redox shuttles. Generation of Ce 4+ species by a mediated electron transfer process quenches the nanoparticle luminescence. Altering the applied potential enables repeatable luminescence on–off switching.