Formation of Cs₃Cu₂I₅ microcrystals in CsI crystals through the aggregation of Cu⁺ ions

Abstract

We have investigated X-ray diffraction (XRD) patterns of CsI bulk crystals highly doped with Cu + ions (1 and 10 mol%) and a Cs 3 Cu 2 I 5 bulk crystal in order to clarify the formation of microcrystals of Cu-based compounds through the aggregation of Cu + ions in CsI host crystals. We have also measured photoluminescence (PL) and photoluminescence excitation (PLE) spectra of the above three crystals and a CsI bulk crystal lowly doped with Cu + ions (0.001 mol%) at 10 K. The XRD patterns, PL, and PLE spectra show that the CsI bulk crystals doped with Cu + ions (1 and 10 mol%) comprise Cs 3 Cu 2 I 5 microcrystals formed in CsI crystals. On the basis of those results, we discuss the formation of microcrystals of Cu-based compounds through the aggregation of Cu + ions in CsI bulk crystals with CsCl-type structure.

Room-Temperature Solid-State Synthesis of Cs3Cu2I5 Thin Films and Formation Mechanism for Its Unique Local Structure

“…The EDS composition analysis revealed that Cs and Cu were dissolved into CuI and CsI, respectively. The formation of the CuI–CsI solid solution was reported in scintillator-related studies . We reported that high-concentration Cs + doping in CuI forms complex defects of interstitial Cs + and Cu vacancies in the previous paper …”

“…The formation of the CuI−CsI solid solution was reported in scintillator-related studies. 32 We reported that high-concentration Cs + doping in CuI forms complex defects of interstitial Cs + and Cu vacancies in the previous paper. 33 exist in the CsCl-type lattice.…”