TY - JOUR
T1 - Deposition Mechanism of Aluminum Oxide on Quantum Dot Films at Atmospheric Pressure and Room Temperature
AU - Valdesueiro Gonzalez, D.
AU - Prabhu, Mahesh Krishna
AU - Guerra-Nunez, Carlos
AU - Sandeep, C. S Suchand
AU - Kinge, Sachin
AU - Siebbeles, Laurens D A
AU - De Smet, Louis C P M
AU - Meesters, Gabrie M H
AU - Kreutzer, Michiel T.
AU - Houtepen, Arjan J.
AU - Van Ommen, J. Ruud
PY - 2016/3/3
Y1 - 2016/3/3
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=84960155263&partnerID=8YFLogxK
UR - http://resolver.tudelft.nl/uuid:96a05294-960e-412e-beb7-5f57ed77ef92
U2 - 10.1021/acs.jpcc.5b11653
DO - 10.1021/acs.jpcc.5b11653
M3 - Article
AN - SCOPUS:84960155263
SN - 1932-7447
VL - 120
SP - 4266
EP - 4275
JO - The Journal of Physical Chemistry C
JF - The Journal of Physical Chemistry C
IS - 8
ER -