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

Journal article (2017)

Authors

H. Luo RST/Fundamental Aspects of Materials and Energy - AS
A.J.J. bos RST/Fundamental Aspects of Materials and Energy - AS
P. Dorenbos RST/Fundamental Aspects of Materials and Energy - AS
Research Group
RST/Fundamental Aspects of Materials and Energy (AS) (TU Delft)
Copyright: © 2017 H. Luo, A.J.J. bos, P. Dorenbos
DOI: https://doi.org/10.1021/acs.jpcc.7b01577
More Info
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Published Date

2017

Language

English

Faculty

Applied Sciences

Department

RST/Radiation, Science and Technology

Research Group

RST/Fundamental Aspects of Materials and Energy

Abstract

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 the intrinsic defects recombine at Ce4+, Pr4+, or Tb4+ via the conduction band. On the other hand, Ti4+ and Eu3+ act as recombination centers and electron trapping centers while host intrinsic defects act as hole trapping centers. For these codopants we find evidence that recombination is by means of hole release instead of electron release. The released holes recombine with the trapped electrons on Ti3+ or Eu2+ and yield broad Ti4+ yellow-red charge transfer (CT) emission or characteristic Eu3+ 4f–4f emission. We will conclude that the afterglow in Y2O2S:Ti4+, Eu3+ is due to hole release instead of more common electron release.