Deposition Mechanism of Aluminum Oxide on Quantum Dot Films at Atmospheric Pressure and Room Temperature

Journal article (2016)

Authors

D. Valdesueiro Gonzalez ChemE/Product and Process Engineering - AS
M.K. Prabhu ChemE/Product and Process Engineering - AS
J.R. van Ommen ChemE/Product and Process Engineering - AS
C.R. Guerra Nunez ChemE/Product and Process Engineering - AS , Swiss Federal Laboratories for Materials Science and Technology (Empa)
C. S Suchand Sandeep University of Potsdam
S.S. Kinge ChemE/Opto-electronic Materials - AS
L.D.A. Siebbeles ChemE/Opto-electronic Materials - AS
L.C.P.M. de Smet OLD ChemE/Organic Materials and Interfaces
G.M.H. Meesters ChemE/Product and Process Engineering - AS
M.T. Kreutzer ChemE/Chemical Engineering
A.J. Houtepen ChemE/Opto-electronic Materials - AS
Research Group
ChemE/Product and Process Engineering (AS) (TU Delft)
Copyright: © 2016 D. Valdesueiro Gonzalez, M.K. Prabhu, C.R. Guerra Nunez, C. S Suchand Sandeep, S.S. Kinge, L.D.A. Siebbeles, L.C.P.M. de Smet, G.M.H. Meesters, M.T. Kreutzer, A.J. Houtepen, J.R. van Ommen
DOI: https://doi.org/10.1021/acs.jpcc.5b11653
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Published Date

03-03-2016

Language

English

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Faculty

Applied Sciences

Department

ChemE/Chemical Engineering

Research Group

ChemE/Product and Process Engineering

Abstract

Stability of quantum dot (QD) films is an issue of concern for applications in devices such as solar cells, LEDs, and transistors. This paper analyzes and optimizes the passivation of such QD films using gas-phase deposition, resulting in enhanced stability. Crucially, we deposited alumina at economically attractive conditions, room temperature and atmospheric pressure, on (1,2-ethanediamine) capped PbSe QD films using an approach based on atomic layer deposition (ALD), with trimethylaluminum (TMA) and water as precursors. We performed coating experiments from 1 to 25 cycles on the QD films, finding that alumina formed from the first exposure of TMA. X-ray photoelectron spectroscopy points to the presence of oxygen-rich compounds on the bare QD films, most likely from entrapped solvent molecules during the assembly of the QD films. These oxygenated compounds and the amine groups of the organic ligands react with TMA in the first cycle, resulting in a fast growth of alumina. Using 10 cycles resulted in a QD film that was optically stable for at least 27 days. Depositing alumina at ambient conditions is preferred, since the production of the QD films is also carried out at room temperature and atmospheric pressure, allowing combination of both processes in a single go.