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Electronic Energy Alignment At The PbSe Quantum Dots/ZnO(101̅0) Interface

Brooke A. Timp, X. Zhu
Published 2010 ·

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Abstract A number of solar energy conversion strategies depend on exciton dissociation across interfaces between semiconductor quantum dots (QDs) and other electron or hole conducting materials. A critical factor governing exciton dissociation and charge transfer in these systems is the alignment of electronic energy levels across the interface. We probe interfacial electronic energy alignment in a model system, sub-monolayer films of PbSe QDs adsorbed on single crystal ZnO(1010) surfaces using ultraviolet photoemission spectroscopy. We establish electronic energy alignment as a function of quantum dot size and surface chemistry. We find that replacing insulating oleic-acid capping molecules on the QDs by the short hydrazine or ethanedithiol molecules results in pinning of the valence band maximum (VBM) of QDs to ZnO substrate states, independent of QD size. This is in contrast to similar measurements on TiO 2 (110) where the alignment of the PbSe QD VBM to that of the TiO 2 substrate depends on QD size. We interpret these findings as indicative of strong electronic coupling of QDs with the ZnO surface but less with the TiO 2 surface. Based on the measured energy alignment, we predict that electron injection from the 1s e level in photo-excited PbSe QDs to ZnO can occur with small QDs (diameter ϕ  = 3.4 nm), but energetically unfavorably for larger dots ( ϕ  = 6.7 nm). In the latter, hot electrons above the 1s e level are necessary for interfacial electron injection.

This paper is referenced by
Atomic layer deposition in nanostructured photovoltaics: tuning optical, electronic and surface properties.
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Determination of heterojunction band offsets between CdS bulk and PbS quantum dots using photoelectron spectroscopy
Khagendra P. Bhandari (2014)
Ambipolar and unipolar PbSe nanowire field-effect transistors.
D. Kim (2011)
Determination of the Electronic Energetics of CdTe Nanoparticle Assemblies on Au Electrodes by Photoemission, Electrochemical, and Photocurrent Studies
Y. Wang (2012)
Robust, functional nanocrystal solids by infilling with atomic layer deposition.
Y. Liu (2011)
Multiple Exciton Generation in Quantum Dot Solar Cells
Octavi E. Semonin (2012)
Band Edge Energetics of Heterostructured Nanorods: Photoemission Spectroscopy and Waveguide Spectroelectrochemistry of Au-Tipped CdSe Nanorod Monolayers.
Ramanan Ehamparam (2015)
Characterizing the Energetic Landscape in Solution Processable Solar Cells via Frequency Dependent Impedance Measurements
E. S. Wong (2018)
Charge dynamics at heterojunctions for PbS/ZnO colloidal quantum dot solar cells probed with time-resolved surface photovoltage spectroscopy
B. Spencer (2016)
Synthesis of ZnO nanorods and their application in quantum dot sensitized solar cells
M. Thambidurai (2012)
Energy level modification in lead sulfide quantum dot thin films through ligand exchange.
P. Brown (2014)
Electronic Structure of PbS Colloidal Quantum Dots on Indium Tin Oxide and Titanium Oxide
T. G. Kim (2014)
Direct work function measurement by gas phase photoelectron spectroscopy and its application on PbS nanoparticles.
S. Axnanda (2013)
Band to Band Tunneling at the Zinc Oxide (ZnO) and Lead Selenide (PbSe) Quantum Dot Contact; Interfacial Charge Transfer at a ZnO/PbSe/ZnO Probe Device
Minkyong Kim (2019)
Measurement of the valence band-offset in a PbSe/ZnO heterojunction by x-ray photoelectron spectroscopy
L. Li (2012)
A p‐Type Quantum Dot/Organic Donor:Acceptor Solar‐Cell Structure for Extended Spectral Response
H. Y. Chen (2011)
Quantum-Tuned Multijunction Solar Cells
Ghada I. Koleilat (2012)
Incorporation of Inorganic Nanoparticles into Bulk Heterojunction Organic Solar Cells
J. Freitas (2013)
Controlled growth of ZnO/Zn₁-xPbxSe core-shell nanowires and their interfacial electronic energy alignment.
Z. Chen (2012)
Colloidal nanocrystal quantum dot assemblies as artificial solids
T. Hanrath (2012)
A layer-by-layer ZnO nanoparticle-PbS quantum dot self-assembly platform for ultrafast interfacial electron injection.
Mohamed Eita (2015)
Revisiting the Valence and Conduction Band Size Dependence of PbS Quantum Dot Thin Films.
E. Miller (2016)
Artificial atoms on semiconductor surfaces
W. Tisdale (2010)
Silica encapsulation of thiol-stabilized lead selenide (PbSe) quantum dots in aqueous solution.
Oliva M. Primera-Pedrozo (2013)
Energy level engineering in colloidal quantum dot solar cells
P. Brown (2016)
Eliminating Fermi-level pinning in PbS quantum dots using an alumina interfacial layer
B. Bloom (2016)
PbS nanoparticles capped with tetrathiafulvalenetetracarboxylate: utilizing energy level alignment for efficient carrier transport.
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