n-Type Transition Metal Oxide as a Hole Extraction Layer in PbS Quantum Dot Solar Cells

Jianbo Gao; Craig L. Perkins; Joseph M. Luther; Mark C. Hanna; Hsiang Yu Chen; Octavi E. Semonin; Arthur J. Nozik; Randy J. Ellingson; Matthew C. Beard

doi:10.1021/nl2015729

n-Type Transition Metal Oxide as a Hole Extraction Layer in PbS Quantum Dot Solar Cells

Jianbo Gao, Craig L. Perkins, Joseph M. Luther, Mark C. Hanna, Hsiang Yu Chen, Octavi E. Semonin, Arthur J. Nozik, Randy J. Ellingson, Matthew C. Beard

Research output: Contribution to journal › Article › peer-review

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Abstract

The n-type transition metal oxides (TMO) consisting of molybdenum oxide (MoO_x) and vanadium oxide (V₂O_x) are used as an efficient hole extraction layer (HEL) in heterojunction ZnO/PbS quantum dot solar cells (QDSC). A 4.4% NREL-certified device based on the MoO_x HEL is reported with Al as the back contact material, representing a more than 65% efficiency improvement compared with the case of Au contacting the PbS quantum dot (QD) layer directly. We find the acting mechanism of the hole extraction layer to be a dipole formed at the MoO_x and PbS interface enhancing band bending to allow efficient hole extraction from the valence band of the PbS layer by MoO_x. The carrier transport to the metal anode is likely enhanced through shallow gap states in the MoO_x layer.

Original language	American English
Pages (from-to)	3263-3266
Number of pages	4
Journal	Nano Letters
Volume	11
Issue number	8
DOIs	https://doi.org/10.1021/nl2015729 https://doi.org/10.1021/nl2015729
State	Published - 2011

NREL Publication Number

NREL/JA-5900-52074

Keywords

band bending
gap states
hole extraction layer
quantum dot
solar cell
Transition metal oxide

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title = "n-Type Transition Metal Oxide as a Hole Extraction Layer in PbS Quantum Dot Solar Cells",

abstract = "The n-type transition metal oxides (TMO) consisting of molybdenum oxide (MoOx) and vanadium oxide (V2Ox) are used as an efficient hole extraction layer (HEL) in heterojunction ZnO/PbS quantum dot solar cells (QDSC). A 4.4% NREL-certified device based on the MoOx HEL is reported with Al as the back contact material, representing a more than 65% efficiency improvement compared with the case of Au contacting the PbS quantum dot (QD) layer directly. We find the acting mechanism of the hole extraction layer to be a dipole formed at the MoOx and PbS interface enhancing band bending to allow efficient hole extraction from the valence band of the PbS layer by MoOx. The carrier transport to the metal anode is likely enhanced through shallow gap states in the MoOx layer.",

keywords = "band bending, gap states, hole extraction layer, quantum dot, solar cell, Transition metal oxide",

author = "Jianbo Gao and Perkins, {Craig L.} and Luther, {Joseph M.} and Hanna, {Mark C.} and Chen, {Hsiang Yu} and Semonin, {Octavi E.} and Nozik, {Arthur J.} and Ellingson, {Randy J.} and Beard, {Matthew C.}",

year = "2011",

doi = "10.1021/nl2015729",

language = "American English",

volume = "11",

pages = "3263--3266",

journal = "Nano Letters",

issn = "1530-6984",

publisher = "American Chemical Society",

number = "8",

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TY - JOUR

T1 - n-Type Transition Metal Oxide as a Hole Extraction Layer in PbS Quantum Dot Solar Cells

AU - Gao, Jianbo

AU - Perkins, Craig L.

AU - Luther, Joseph M.

AU - Hanna, Mark C.

AU - Chen, Hsiang Yu

AU - Semonin, Octavi E.

AU - Nozik, Arthur J.

AU - Ellingson, Randy J.

AU - Beard, Matthew C.

PY - 2011

Y1 - 2011

N2 - The n-type transition metal oxides (TMO) consisting of molybdenum oxide (MoOx) and vanadium oxide (V2Ox) are used as an efficient hole extraction layer (HEL) in heterojunction ZnO/PbS quantum dot solar cells (QDSC). A 4.4% NREL-certified device based on the MoOx HEL is reported with Al as the back contact material, representing a more than 65% efficiency improvement compared with the case of Au contacting the PbS quantum dot (QD) layer directly. We find the acting mechanism of the hole extraction layer to be a dipole formed at the MoOx and PbS interface enhancing band bending to allow efficient hole extraction from the valence band of the PbS layer by MoOx. The carrier transport to the metal anode is likely enhanced through shallow gap states in the MoOx layer.

AB - The n-type transition metal oxides (TMO) consisting of molybdenum oxide (MoOx) and vanadium oxide (V2Ox) are used as an efficient hole extraction layer (HEL) in heterojunction ZnO/PbS quantum dot solar cells (QDSC). A 4.4% NREL-certified device based on the MoOx HEL is reported with Al as the back contact material, representing a more than 65% efficiency improvement compared with the case of Au contacting the PbS quantum dot (QD) layer directly. We find the acting mechanism of the hole extraction layer to be a dipole formed at the MoOx and PbS interface enhancing band bending to allow efficient hole extraction from the valence band of the PbS layer by MoOx. The carrier transport to the metal anode is likely enhanced through shallow gap states in the MoOx layer.

KW - band bending

KW - gap states

KW - hole extraction layer

KW - quantum dot

KW - solar cell

KW - Transition metal oxide

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U2 - 10.1021/nl2015729

DO - 10.1021/nl2015729

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VL - 11

SP - 3263

EP - 3266

JO - Nano Letters

JF - Nano Letters

IS - 8

ER -

n-Type Transition Metal Oxide as a Hole Extraction Layer in PbS Quantum Dot Solar Cells

Abstract

NREL Publication Number

Keywords

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