Abstract
The interface stoichiometry of cuprous oxide (Cu2O) was controlled by adjusting the O2 and Zn partial pressures during ZnO sputter deposition and measured by high-resolution X-ray photoelectron spectroscopy of ultrathin (<3 nm) ZnO films on Cu2O. Open-circuit voltage measurements for ZnO/Cu2O heterojunctions under AM1.5 illumination were measured and it was found that a stoichiometric interface can achieve the voltage entitlement dictated by the band alignment, whereas the non-stoichiometric interface showed large open-circuit voltage deficits. These results highlight not only the need for stoichiometric interfaces in Cu2O devices, but also a reproducible experimental method for achieving stoichiometric interfaces that could be applied to any potential heterojunction partner. Additionally, valence-band offset measurements indicated changing the interface stoichiometry shifted the band alignment between Cu2O and ZnO, which accounts for the variation in previously reported band offset values.
Original language | English |
---|---|
Pages (from-to) | 3606-3610 |
Number of pages | 5 |
Journal | Energy and Environmental Science |
Volume | 7 |
Issue number | 11 |
DOIs | |
Publication status | Published - 1 Nov 2014 |
Bibliographical note
Publisher Copyright:© 2014 the Partner Organisations.
ASJC Scopus subject areas
- Environmental Chemistry
- Renewable Energy, Sustainability and the Environment
- Nuclear Energy and Engineering
- Pollution