Interfaces Between CdTe and ALD Al₂O₃

Journal Article · 26 September 2018 · IEEE Journal of Photovoltaics

DOI: https://doi.org/10.1109/JPHOTOV.2018.2870139 · OSTI ID:1494739

Perkins, Craig L.  ^[1]; Ablekim, Tursun  ^[1]; Barnes, Teresa M. ^[1]; Kuciauskas, Darius  ^[1]; Lynn, Kelvin G. ^[2]; Nemeth, William ^[1]; Reese, Matthew O.  ^[1]; Swain, Santosh K. ^[2]; Metzger, Wyatt K. ^[1]

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1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
2. Washington State Univ., Pullman, WA (United States)

In this work, we present a combination of X-ray photoelectron spectroscopy (XPS) and time-resolved photoluminescence (TRPL) to probe the details of interface formation between CdTe and alumina deposited by atomic layer deposition (ALD). Alumina ALD using water as the oxygen source causes the elimination of Te oxides that are initially present on air-exposed CdTe surfaces. TRPL on the resulting CdTe interface indicates some degree of passivation. On the other hand, postgrowth treatment of Al₂O₃/CdTe structures with CdCl₂ and oxygen causes regrowth of Te oxides. Some of these structures show improved lifetimes, thereby pointing toward a critical role for Te oxides in interfacial CdTe passivation by Al₂O₃. Lastly, direct measurement of band positions with XPS indicates that the passivation is caused primarily by chemical rather than field effect mechanisms.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
• Grant/Contract Number: AC36-08GO28308
• OSTI ID: 1494739
• Report Number(s): NREL/JA--5K00-72454
• Journal Information: IEEE Journal of Photovoltaics, Journal Name: IEEE Journal of Photovoltaics Journal Issue: 6 Vol. 8; ISSN 2156-3381
• Publisher: IEEECopyright Statement
• Country of Publication: United States
• Language: English