Colloidal Gallium Indium Oxide Nanocrystals: A Multifunctional Light-Emitting Phosphor Broadly Tunable by Alloy Composition
- 8 April 2011
- journal article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 133 (17), 6711-6719
- https://doi.org/10.1021/ja111514u
Abstract
We demonstrate compositionally tunable photoluminescence in complex transparent conducting oxide nanocrystals. Alloyed gallium indium oxide (GIO) nanocrystals with variable crystal structures are prepared by a colloidal method throughout the full composition range and studied by different structural and spectroscopic methods, including photoluminescence and X-ray absorption. The structures and sizes of the GIO nanocrystals can be simultaneously controlled, owing to the difference in the growth kinetics of In(2)O(3) and Ga(2)O(3) nanocrystals and the polymorphic nature of both materials. Using the synthesized nanocrystal series, we demonstrate the structural and compositional dependences of the photoluminescence of GIO nanocrystals. These dependences, induced by the interactions between specific defect sites acting as electron donors and acceptors, are used to achieve broad emission tunability in the visible spectral range at room temperature. The nature of the photoluminescence is identified as donor-acceptor pair recombination and changes with increasing indium content owing to the changes in the energy states of, and interactions between, donors and acceptors. Structural analysis of GIO nanocrystals by extended X-ray absorption fine structure spectroscopy reveals that In(3+) occupies only octahedral, rather than tetrahedral, sites in the spinel-type γ-Ga(2)O(3) nanocrystal host lattice, until reaching the substitutional incorporation limit of ca. 25%. The emission decay dynamics is also strongly influenced by the nanocrystal structure and composition. The oxygen vacancy defects, responsible for the observed photoluminescence properties, are also implicated in other functional properties, particularly conductivity, enabling the application of colloidal GIO nanocrystals as integrated optoelectronic materials.Keywords
This publication has 51 references indexed in Scilit:
- A diamond nanowire single-photon sourceNature Nanotechnology, 2010
- A One‐Step Method for the Growth of Ga2O3‐Nanorod‐Based White‐Light‐Emitting PhosphorsAdvanced Materials, 2009
- High-performance crosslinked colloidal quantum-dot light-emitting diodesNature Photonics, 2009
- Single-exciton optical gain in semiconductor nanocrystalsNature, 2007
- Ultralow threshold on-chip microcavity nanocrystal quantum dot lasersApplied Physics Letters, 2006
- Energy-transfer pumping of semiconductor nanocrystals using an epitaxial quantum wellNature, 2004
- Single-nanowire electrically driven lasersNature, 2003
- Electroluminescence from single monolayers of nanocrystals in molecular organic devicesNature, 2002
- Nanorobotic Manipulation of Microspheres for On-Chip Diamond ArchitecturesAdvanced Materials, 2002
- CII.Luminous carborundum detector and detection effect and oscillations with crystalsThe London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, 1928