Photoemission study of GaN passivation layers and band alignment at GaInP(100) heterointerfaces

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F25%3A00605584" target="_blank" >RIV/68378271:_____/25:00605584 - isvavai.cz</a>

Result on the web

<a href="https://hdl.handle.net/11104/0365696" target="_blank" >https://hdl.handle.net/11104/0365696</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acsami.4c17453" target="_blank" >10.1021/acsami.4c17453</a>

Result language

angličtina

Original language name

Photoemission study of GaN passivation layers and band alignment at GaInP(100) heterointerfaces

Original language description

To date, III-V semiconductor-based tandem devices with GaInP top photoabsorbers show the highest solar-to-electricity or solar-to-fuel conversion efficiencies. In photoelectrochemical (PEC) cells, however, III-V semiconductors are sensitive, in terms of photochemical stability and, therefore, require suitable functional layers for electronic and chemical passivation. GaN films are discussed as promising options for this purpose. The band alignment between such a protection layer and the III-V semiconductor should be aligned to minimize corrosion and nonradiative interfacial recombination and to promote selective charge carrier transport. Here, we investigate the band alignment between GaN passivation layers and n-type doped GaInP(100) photoabsorbers and grew n-type GaInP(100) epitaxially by metalorganic vapor phase epitaxy on oxidized GaAs(100) substrates to mimic a realistic preparation sequence. We prepared 1-20 nm GaN films on top employing atomic layer deposition and studied the band alignment at the GaN/GaInP(100) heterointerface by X-ray and ultraviolet photoelectron spectroscopy. Due to the limited emission depth of photoelectrons, we determined the band alignment by a series of measurements, in which we increased the thickness of the GaN films successively. The n-GaInP(100) surfaces, prepared with a well-known phosphorus-terminated p(2 x 2)/c(4 x 2) reconstruction, show an upward surface band bending (BB) of 0.38 eV and a Fermi level pinning due to the present surface states. Upon oxidation, the surface states are partially passivated, resulting in a reduction of the BB to 0.16 eV and a valence band offset (VBO) between the GaInP(100) and the thin oxide layer of 2.01 eV. Applying Kraut's approach, we identified a VBO of 1.90 eV and a conduction band offset of 0.44 eV between GaInP(100) with a thin oxide layer and the GaN passivation layer. We conclude that the GaN is a well-suited passivation layer for PEC cells and facilitates selective transport of photogenerated electrons.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

ACS Applied Materials and Interfaces

ISSN

1944-8244

e-ISSN

1944-8252

Volume of the periodical

17

Issue of the periodical within the volume

4

Country of publishing house

US - UNITED STATES

Number of pages

11

Pages from-to

7087-7097

UT code for WoS article

001395920400001

EID of the result in the Scopus database

2-s2.0-85216924232