Charge carrier trapping processes in lanthanide doped La-, Gd-, Y-, and LuPO4

Tianshuai Lyu, Pieter Dorenbos

Research output: Contribution to journalArticleScientificpeer-review

41 Citations (Scopus)
62 Downloads (Pure)

Abstract

Various methods for deliberate design electron and hole trapping materials are explored with a study on double lanthanide doped rare earth ortho phosphates. Cerium acts as recombination center while lanthanide codopants as electron trapping centers in LaPO4:0.005Ce3+,0.005Ln3+. The electron trap depth generated by lanthanide codopants can be tailored by the choice of lanthanide, and for fixed set of lanthanide dopants like in Gd1-xLaxPO4:0.005Ce3+,0.005Ho3+ solid solutions by changing x leading to conduction band (CB) engineering. Here, the electrons liberated from Ho2+ recombine through the conduction band at Ce4+ to yield Ce3+ 5d-4f emission. In contrast, samarium, europium and ytterbium are recombination centers, while Tb3+ and Pr3+ act as hole trapping centers in double lanthanide doped YPO4. For Tb3+ and Pr3+ codopants recombination is realized via hole release rather than the more common reported electron release. The holes recombine via the valence band with the electrons trapped at Yb2+, Sm2+, or Eu2+ to generate 4f-4f luminescence from Yb3+, Sm3+, or Eu3+. Lu3+ was introduced in YPO4 to tailor the valence band (VB) energy and to tune the hole trap depths of Tb3+ and Pr3+ in Y1-xLuxPO4:0.005Ln3+ solid solutions. Our results promote the deliberate design electron and hole trapping materials from deep understanding of trap level locations and on the transport and trapping processes of charge carriers.
Original languageEnglish
Number of pages23
JournalJournal of Materials Chemistry C: materials for optical and electronic devices
DOIs
Publication statusPublished - 6 Dec 2017

Fingerprint Dive into the research topics of 'Charge carrier trapping processes in lanthanide doped La-, Gd-, Y-, and LuPO4'. Together they form a unique fingerprint.

Cite this