Title: Probing charge transfer in a novel class of luminescent perovskite-based heterostructures composed of quantum dots bound to RE-activated CaTiO₃ phosphors

Abstract

We report on the synthesis and structural characterization of novel semiconducting heterostructures composed of cadmium selenide (CdSe) quantum dots (QDs) attached onto the surfaces of novel high-surface area, porous rare-earth-ion doped alkaline earth titanate micron-scale spherical motifs, i.e. both Eu-doped and Pr-doped CaTiO₃, composed of constituent, component nanoparticles. These unique metal oxide perovskite building blocks were created by a multi-pronged synthetic strategy involving molten salt and hydrothermal protocols. Subsequently, optical characterization of these heterostructures indicated a clear behavioral dependence of charge transfer in these systems upon a number of parameters such as the nature of the dopant, the reaction temperature, and particle size. Specifically, 2.7 nm diameter ligand-functionalized CdSe QDs were anchored onto sub-micron sized CaTiO₃-based spherical assemblies, prepared by molten salt protocols. We found that both the Pr- and Eu-doped CaTiO₃ displayed pronounced PL emissions, with maximum intensities observed using optimized lanthanide concentrations of 0.2 mol% and 6 mol%, respectively. Analogous experiments were performed on Eu-doped BaTiO₃ and SrTiO₃ motifs, but CaTiO₃ still performed as the most effective host material amongst the three perovskite systems tested. Furthermore, the ligand-capped CdSe QD-doped CaTiO₃ heterostructures exhibited effective charge transfer between the two individual constituent nanoscale components, an assertion corroborated by themore » corresponding quenching of their measured PL signals.« less

Authors:

Crystal S. Lewis; Wong, Stanislaus S. ^[1]; Liu, Haiqing ^[1]; Han, Jinkyu ^[2]; Wang, Lei ^[1]; Yue, Shiyu ^[1]; Brennan, Nicholas A. ^[1]

---

+ Show Author Affiliations

1. State Univ. of New York at Stony Brook, Stony Brook, NY (United States)
2. Brookhaven National Lab. (BNL), Upton, NY (United States)

Publication Date:

Mon Jan 04 00:00:00 EST 2016

Research Org.:

Brookhaven National Lab. (BNL), Upton, NY (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1235862

Report Number(s):

BNL-111622-2015-JA
Journal ID: ISSN 2040-3364; NANOHL; R&D Project: PM037; KC0201030

Grant/Contract Number:  

SC00112704

Resource Type:

Accepted Manuscript

Journal Name:

Nanoscale

Additional Journal Information:

Journal Volume: 8; Journal Issue: 4; Journal ID: ISSN 2040-3364

Publisher:

Royal Society of Chemistry

Country of Publication:

United States

Language:

English

Subject:

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CaTiO₃; praseodymium; europium; rare earth ion-doped materials; doped perovskites; metal titanates; fluorescent and luminescent materials; optical properties