Electronic structure and site occupancy of lanthanide-doped (Sr, ca)₃(Y, lu)₂Ge₃O₁₂ garnets: A spectroscopic and first-principles study

Photoluminescence excitation (PLE) and emission spectra (PL) of undoped (Sr, Ca)₃(Y, Lu)₂Ge₃O₁₂ as well as Eu³⁺- and Ce³⁺-doped samples have been investigated. The PL spectra show that Eu³⁺ enters into both dodecahedral (Ca, Sr) and octahedral (Y, Lu) sites. Ce<sup>3...

Charge Carrier Trapping Processes in RE2O2S (RE = La, Gd, Y, and Lu)

Two different charge carrier trapping processes have been investigated in RE2O2S:Ln3+ (RE = La, Gd, Y, and Lu; Ln = Ce, Pr, and Tb) and RE2O2S:M (M = Ti4+ and Eu3+). Cerium, praseodymium and terbium act as recombination centers and hole trapping centers while host intrinsic defects provide the electron trap. The captured electrons released from...

Luminescent properties and energy level structure of CaZnOS:Eu2+

In this work it is shown that CaZnOS:Eu²⁺ has no Eu²⁺ emission even at low temperature. The observed and earlier reported red emission originates from a CaS:Eu²⁺ impurity phase. By means of washing the as-prepared samples with diluted nitride acid, we were able to remove the CaS impurity phase and study the...

The dual role of Cr³⁺ in trapping holes and electrons in lanthanide co-doped GdAlO₃ and LaAlO₃

Trivalent Nd, Dy, Ho, Er, Tm, Sm and Eu usually act as electron trapping centers in wide band gap compounds, whereas trivalent Ce, Tb and Pr act as hole trapping centers. When a deep electron trap is combined with a shallow hole trap, then during the thermoluminescence glow the hole is released, generating recombination luminescence at the...