Native defects determine phase-dependent photoluminescence behavior of Eu²⁺ and Eu³⁺ in In₂O₃ nanocrystals

Abstract

We demonstrate the coexistence of Eu(2+) and Eu(3+) in corundum and bixbyite-type colloidal In2O3 nanocrystals. The emission properties of dopants in both oxidation states are determined by their interaction with native defects, and are dramatically different in the two nanocrystal phases. This difference arises from the smaller nanocrystal size and higher defect density in metastable corundum-type nanocrystals.

Effect of Dopant Activation and Plasmon Damping on Carrier Polarization in In2O3 Nanocrystals

“…One of the reasons for the coexistence of Mo 5+ with Mo 6+ is the coordinating solvent (oleylamine). Oleylamine acts as a reducing agent, , allowing for a reduction of a significant fraction of Mo 6+ to Mo 5+ , which is then incorporated into the NC host lattice.…”

“…The control of the LSPR absorption energy and band shape through the precise control of dopant location has also been demonstrated . However, dopant ions also have a significant influence on the NC growth, electronic and surface structure, lattice disorder, and trap state formation, − making it difficult to directly compare different systems and elucidate the role of different parameters in excitonic splitting.…”

Inorganic Phosphors for Teaching a Holistic Approach to Functional Materials Investigation: From Synthesis and Characterization to Applications of Thermo- and Mechanoluminescence

“…This observation serves as an excellent vehicle to remind students about the spectroscopic selection rules, and particularly that allowed transitions must involve a change in parity (Laporte selection rule). 14,15 The annealed samples retained their emission for well over 1 min. The lifetime of emission follows the Arrhenius-type equation:…”

“…Annealed samples showed a stronger green emission that is characteristic for Eu 2+ (d–f transitions). This observation serves as an excellent vehicle to remind students about the spectroscopic selection rules, and particularly that allowed transitions must involve a change in parity (Laporte selection rule). , The annealed samples retained their emission for well over 1 min. The lifetime of emission follows the Arrhenius-type equation: where E is the trap depth, k B and T are the Boltzmann constant and temperature, respectively, and s is the frequency factor.…”

“…The prepared samples glow green or red depending on whether or not they were annealed under hydrogen. The origin of this luminescence is from the Eu x+ (x = 2 or 3) ions, , whose luminescence in SrAl 2 O 4 lattice is well-documented. All annealed samples display some level of delayed luminescence from the slow release of trapped carriers.…”