Phase Transformation of a K2GeF6Polymorph for Phosphors Driven by a Simple Precipitation-Dissolution Equilibrium and Ion Exchange

Tianchun Lang, Tianchun Lang, Shuangqiang Fang, Tao Han, Mingguang Wang, Donglin Yang, Jun Wang, Shixiu Cao, Lingling Peng, Bitao Liu, Mingsheng Cai, Yang Zhong, Vladimir I. Korepanov, Aleksey N. Yakovlev

Research output: Contribution to journalArticle

Abstract

Tuning crystal phase transformations is very important for obtaining polymorphs for phosphors with the ideal optical properties and stability. Mn4+-doped K2GeF6 (KGF) is a typical polymorphic phosphor, but the thermodynamic and kinetic mechanism of its phase transformation is still unclear. Herein, the phase transformation of polymorphs varying from P63mc KGF and trigonal KGF to P63mc Si4+-doped KGF is realized by introducing the synergistic action of an HF solution and Si4+ ions. The full structural refinements of KGF polymorphs at room temperature and the electronic band structure calculations were performed. The results show that the Si4+-doped hexagonal KGF polymorph with good photoluminescence properties is the most stable phase according to the calculated total energy landscape and relative formation energy. The morphologic changes were monitored in situ to clearly understand the rapid phase transformation mechanism, which proves that the phase transformation is driven by a simple precipitation-dissolution equilibrium and ionic exchange.

Original languageEnglish
Pages (from-to)8298-8307
Number of pages10
JournalInorganic Chemistry
Volume59
Issue number12
DOIs
Publication statusPublished - 15 Jun 2020

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

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