Amorphous TiO2 coatings stabilize Si, GaAs, and GaP photoanodes for efficient water oxidation

Shu Hu, Matthew R. Shaner, Joseph A. Beardslee, Michael Lichterman, Bruce S. Brunschwig, Nathan S Lewis

Research output: Contribution to journalArticle

659 Citations (Scopus)

Abstract

Although semiconductors such as silicon (Si), gallium arsenide (GaAs), and gallium phosphide (GaP) have band gaps that make them efficient photoanodes for solar fuel production, these materials are unstable in aqueous media.We show that TiO2 coatings (4 to 143 nanometers thick) grown by atomic layer deposition prevent corrosion, have electronic defects that promote hole conduction, and are sufficiently transparent to reach the light-limited performance of protected semiconductors. In conjunction with a thin layer or islands of Ni oxide electrocatalysts, Si photoanodes exhibited continuous oxidation of 1.0 molar aqueous KOH to O2 for more than 100 hours at photocurrent densities of >30 milliamperes per square centimeter and ∼100% Faradaic efficiency. TiO2-coated GaAs and GaP photoelectrodes exhibited photovoltages of 0.81 and 0.59 V and light-limiting photocurrent densities of 14.3 and 3.4 milliamperes per square centimeter, respectively, for water oxidation.

Original languageEnglish
Pages (from-to)1005-1009
Number of pages5
JournalScience
Volume344
Issue number6187
DOIs
Publication statusPublished - 2014

Fingerprint

gallium phosphides
gallium
photocurrents
fuel production
coatings
oxidation
electrocatalysts
photovoltages
silicon
atomic layer epitaxy
water
corrosion
conduction
oxides
defects
electronics

ASJC Scopus subject areas

  • General

Cite this

Hu, S., Shaner, M. R., Beardslee, J. A., Lichterman, M., Brunschwig, B. S., & Lewis, N. S. (2014). Amorphous TiO2 coatings stabilize Si, GaAs, and GaP photoanodes for efficient water oxidation. Science, 344(6187), 1005-1009. https://doi.org/10.1126/science.1251428

Amorphous TiO2 coatings stabilize Si, GaAs, and GaP photoanodes for efficient water oxidation. / Hu, Shu; Shaner, Matthew R.; Beardslee, Joseph A.; Lichterman, Michael; Brunschwig, Bruce S.; Lewis, Nathan S.

In: Science, Vol. 344, No. 6187, 2014, p. 1005-1009.

Research output: Contribution to journalArticle

Hu, S, Shaner, MR, Beardslee, JA, Lichterman, M, Brunschwig, BS & Lewis, NS 2014, 'Amorphous TiO2 coatings stabilize Si, GaAs, and GaP photoanodes for efficient water oxidation', Science, vol. 344, no. 6187, pp. 1005-1009. https://doi.org/10.1126/science.1251428
Hu, Shu ; Shaner, Matthew R. ; Beardslee, Joseph A. ; Lichterman, Michael ; Brunschwig, Bruce S. ; Lewis, Nathan S. / Amorphous TiO2 coatings stabilize Si, GaAs, and GaP photoanodes for efficient water oxidation. In: Science. 2014 ; Vol. 344, No. 6187. pp. 1005-1009.
@article{0e09e604bd83484cbff515f7e9d43acb,
title = "Amorphous TiO2 coatings stabilize Si, GaAs, and GaP photoanodes for efficient water oxidation",
abstract = "Although semiconductors such as silicon (Si), gallium arsenide (GaAs), and gallium phosphide (GaP) have band gaps that make them efficient photoanodes for solar fuel production, these materials are unstable in aqueous media.We show that TiO2 coatings (4 to 143 nanometers thick) grown by atomic layer deposition prevent corrosion, have electronic defects that promote hole conduction, and are sufficiently transparent to reach the light-limited performance of protected semiconductors. In conjunction with a thin layer or islands of Ni oxide electrocatalysts, Si photoanodes exhibited continuous oxidation of 1.0 molar aqueous KOH to O2 for more than 100 hours at photocurrent densities of >30 milliamperes per square centimeter and ∼100{\%} Faradaic efficiency. TiO2-coated GaAs and GaP photoelectrodes exhibited photovoltages of 0.81 and 0.59 V and light-limiting photocurrent densities of 14.3 and 3.4 milliamperes per square centimeter, respectively, for water oxidation.",
author = "Shu Hu and Shaner, {Matthew R.} and Beardslee, {Joseph A.} and Michael Lichterman and Brunschwig, {Bruce S.} and Lewis, {Nathan S}",
year = "2014",
doi = "10.1126/science.1251428",
language = "English",
volume = "344",
pages = "1005--1009",
journal = "Science",
issn = "0036-8075",
publisher = "American Association for the Advancement of Science",
number = "6187",

}

TY - JOUR

T1 - Amorphous TiO2 coatings stabilize Si, GaAs, and GaP photoanodes for efficient water oxidation

AU - Hu, Shu

AU - Shaner, Matthew R.

AU - Beardslee, Joseph A.

AU - Lichterman, Michael

AU - Brunschwig, Bruce S.

AU - Lewis, Nathan S

PY - 2014

Y1 - 2014

N2 - Although semiconductors such as silicon (Si), gallium arsenide (GaAs), and gallium phosphide (GaP) have band gaps that make them efficient photoanodes for solar fuel production, these materials are unstable in aqueous media.We show that TiO2 coatings (4 to 143 nanometers thick) grown by atomic layer deposition prevent corrosion, have electronic defects that promote hole conduction, and are sufficiently transparent to reach the light-limited performance of protected semiconductors. In conjunction with a thin layer or islands of Ni oxide electrocatalysts, Si photoanodes exhibited continuous oxidation of 1.0 molar aqueous KOH to O2 for more than 100 hours at photocurrent densities of >30 milliamperes per square centimeter and ∼100% Faradaic efficiency. TiO2-coated GaAs and GaP photoelectrodes exhibited photovoltages of 0.81 and 0.59 V and light-limiting photocurrent densities of 14.3 and 3.4 milliamperes per square centimeter, respectively, for water oxidation.

AB - Although semiconductors such as silicon (Si), gallium arsenide (GaAs), and gallium phosphide (GaP) have band gaps that make them efficient photoanodes for solar fuel production, these materials are unstable in aqueous media.We show that TiO2 coatings (4 to 143 nanometers thick) grown by atomic layer deposition prevent corrosion, have electronic defects that promote hole conduction, and are sufficiently transparent to reach the light-limited performance of protected semiconductors. In conjunction with a thin layer or islands of Ni oxide electrocatalysts, Si photoanodes exhibited continuous oxidation of 1.0 molar aqueous KOH to O2 for more than 100 hours at photocurrent densities of >30 milliamperes per square centimeter and ∼100% Faradaic efficiency. TiO2-coated GaAs and GaP photoelectrodes exhibited photovoltages of 0.81 and 0.59 V and light-limiting photocurrent densities of 14.3 and 3.4 milliamperes per square centimeter, respectively, for water oxidation.

UR - http://www.scopus.com/inward/record.url?scp=84901606058&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84901606058&partnerID=8YFLogxK

U2 - 10.1126/science.1251428

DO - 10.1126/science.1251428

M3 - Article

AN - SCOPUS:84901606058

VL - 344

SP - 1005

EP - 1009

JO - Science

JF - Science

SN - 0036-8075

IS - 6187

ER -